Author Topic: Owner's Manual Scheduled Maintenance - Time vs. Mileage?  (Read 1240 times)

FactorsOf2

  • 5 O'Clock Shadow
  • *
  • Posts: 25
Owner's Manual Scheduled Maintenance - Time vs. Mileage?
« on: October 02, 2019, 07:36:33 AM »
Some background: We have been car free for 5 years, but soon will have 2 kids under 2 and we've relocated to a less accessible area. Last week we pulled the trigger on a 2014 Altima with 23k miles (single owner, strong service record). We don't expect to put many miles on the car; maybe 30 miles each weekend plus a 500 mile roadtrip three times a year for a total of ~ 3k miles per year.

We aren't technically first-time car owners, but we might as well be in terms of how to properly care for a car. I am planning to follow the scheduled maintenance timetable in our owner's manual (DIY'ing engine and cabin air filters, but nothing else). It is given as a checklist at intervals of 5k miles / 6 month. We expect it to take ~ 1.5 years for us to put 5k miles on the car. Obviously my frugal heart is hoping that we can just go by the mileage intervals rather than the 6 month intervals. What are peoples' thoughts on this? Are there certain things that are particularly age-sensitive?

Thank you all!

Sibley

  • Magnum Stache
  • ******
  • Posts: 4590
  • Location: Northwest Indiana
Re: Owner's Manual Scheduled Maintenance - Time vs. Mileage?
« Reply #1 on: October 02, 2019, 09:29:57 AM »
NOT a car expert, so others can over rule me.

Rubber dries out over time. Even if the car is sitting, it will degrade. That's why they provide the time OR mileage, whichever is first.

However, I suspect that the time standard they provide is conservative. I regularly exceed the time portion for oil changes, and it doesn't seem to be an issue.

sisto

  • Pencil Stache
  • ****
  • Posts: 973
  • Age: 51
  • Location: Sacramento, CA
Re: Owner's Manual Scheduled Maintenance - Time vs. Mileage?
« Reply #2 on: October 02, 2019, 09:44:25 AM »
You really only need to change the oil or filters when they are dirty. I also am a very low mileage driver. I change oil 1x per year. Still before the mileage, but I don't want to push longer.

Boofinator

  • Handlebar Stache
  • *****
  • Posts: 1432
Re: Owner's Manual Scheduled Maintenance - Time vs. Mileage?
« Reply #3 on: October 02, 2019, 09:46:04 AM »
Mileage for almost everything*. The exception I would use is for brake fluid (tends to degrade more due to time than mileage) and of course tire pressures. For tires, I wouldn't exceed ten years from the date of manufacture (stamped on the sidewall) if the car is stored outside, though I would probably allow for double that if the car is stored under shade.

*Unless you (1) frequently drive for very short mileages, (2) spend a shit-ton of time idling, or (3) drive an insanely low number of miles. Note that 1 and 2 are antimustachian :(, whereas 3 is mustachian :).

BikingEngineer

  • 5 O'Clock Shadow
  • *
  • Posts: 23
Re: Owner's Manual Scheduled Maintenance - Time vs. Mileage?
« Reply #4 on: October 02, 2019, 10:26:54 AM »
The suggestions already given are solid. A lot of this depends on where you live as well, in a desert setting (Arizona, SoCal, etc) you'll run through plastic and rubber at a very fast pace, especially if the car is parked in the sun. In the Midwest/Rustbelt you'll want to look at metal underbody parts more frequently, as road salt can wreak havoc on structural components and seize fasteners very quickly. This can be somewhat mitigated with an oil undercoat, but I wouldn't worry too much about it.

Regardless of where you live, replace your tires after 5-7 years, regardless of where you live. The tires are your only connection to the road, and their traction drops off a ton when they get old. They might look fine, but will be structurally compromised and unsafe. Some tires last longer than others, based on their rubber composition. Look at the mileage warranty offered, divide by 15,000, and that will give you the expected number of years the tires will last. Regardless of how many miles you drive, get new tires at that date or earlier.


I'd inspect accessible filters (engine intake air, cabin air) every 4-6 months and replace as needed (buy a few from Rockauto.com and keep them on hand). They will need replaced if they're heavily discolored, torn, or if taping them against something dislodges sand/dust/dirt. Your particular car takes synthetic oil specifically, so it shouldn't break down based on age alone (except in extreme cases). I'd expect the oil to last 8k-10k miles between changes easily but that can be drastically shortened if your trips are too short to heat the oil up, if the oil isn't allowed to get up to temperature you can emulsify humidity into the oil which lowers its lubricity. If you want to be safe, change it every year or two, it won't hurt the car and is very cheap insurance. Change the oil filter at the same time.

As stated previously, brake fluid degrades based on time more than use. It absorbs humidity from the air and becomes less effective as the water content increases. I swap mine every year or two, but I also do this myself. Frequently changing brake fluid will help your brake lines last longer, as old fluid will allow corrosion from the inside of the line. As a bonus the brakes feel a lot better with fresh fluid, a firm brake pedal is a safe brake pedal.

Boofinator

  • Handlebar Stache
  • *****
  • Posts: 1432
Re: Owner's Manual Scheduled Maintenance - Time vs. Mileage?
« Reply #5 on: October 02, 2019, 12:05:40 PM »
To get a bit more into tires.... I agree with BikingEngineer that tires are probably the most important component of your vehicle, as they are your only connection to the road. However, where I disagree is in his strong position on replacing tires every 5-7 years.

The risks that people are willing to accept in life live upon a continuum. When it comes to tires, at one end of the continuum are people who would consider any degradation from performance at brand new as reason to replace their tires; by this logic, one should replace their tires after no more than three years, as that is when a statistically significant decrease in performance and strength can be measured (and if I was a racecar driver, I would follow this replacement advice). At the middle of the continuum falls NHTSA's advice, which requires tire manufacturers to test their tires following FMVSS 139, and based on a successful test advises that tires should be replaced after about 6 to 10 years (with earlier replacement advised for warmer climates). At the far end of the continuum lies my opinion, which observes that NHTSA's FMVSS 139 test is extremely harsh relative to how I drive, to include driving on aged tires for 24 hours at 75 mph, driving for 90 minutes at 75 mph on underinflated tires (20 psi for standard passenger tires) at full load, and driving at 100 mph for 90 minutes at standard pressure. Since I don't drive like a maniac anymore (per George Carlin's definition, https://www.youtube.com/watch?v=XWPCE2tTLZQ) and store my vehicle inside my garage for 95% of the time, I feel 10 years is the minimum amount of time I would use for replacement, and would probably go longer than that if my tread life hadn't been worn. (Obviously, any sidewall bubbles or other serious defects would call for earlier replacement.) Are my performance and reliability decreased relative to new tires? Sure, a bit. But by simply choosing to drive my car I've increased my risks of getting hurt or breaking down much more than by choosing to drive on tires that are less new than the standard by which tires are required to pass using a rather harsh test methodology.

Speaking of tread life, it is extremely important to replace tires if the wear bars are at 2/32", and I would even go 3/32" if I lived somewhere with regular torrential downpours. One hydroplaning event will cost you thousands of dollars and possibly your life.

References:

NHTSA Tire Aging Test Report: https://one.nhtsa.gov/DOT/NHTSA/NVS/Vehicle%20Research%20&%20Test%20Center%20(VRTC)/ca/capubs/811780.pdf

NHTSA test procedures for FMVSS 139: https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/tp-139-02.pdf

MilesTeg

  • Handlebar Stache
  • *****
  • Posts: 1167
Re: Owner's Manual Scheduled Maintenance - Time vs. Mileage?
« Reply #6 on: October 02, 2019, 05:33:42 PM »
Some background: We have been car free for 5 years, but soon will have 2 kids under 2 and we've relocated to a less accessible area. Last week we pulled the trigger on a 2014 Altima with 23k miles (single owner, strong service record). We don't expect to put many miles on the car; maybe 30 miles each weekend plus a 500 mile roadtrip three times a year for a total of ~ 3k miles per year.

We aren't technically first-time car owners, but we might as well be in terms of how to properly care for a car. I am planning to follow the scheduled maintenance timetable in our owner's manual (DIY'ing engine and cabin air filters, but nothing else). It is given as a checklist at intervals of 5k miles / 6 month. We expect it to take ~ 1.5 years for us to put 5k miles on the car. Obviously my frugal heart is hoping that we can just go by the mileage intervals rather than the 6 month intervals. What are peoples' thoughts on this? Are there certain things that are particularly age-sensitive?

Thank you all!


Some things can go entirely on mileage,  most can't.

Any rubber item, lubricant or fluid of any kind needs to be replaced on a time schedule even on low mileage vehicles.

Rubber dries out and rots and fluids get contaminated by air, moisture and combustion byproducts and break down or lose their effectiveness.

That means oil, belts, hoses, tires, coolant, brake fluid, diff fluid, transmission fluid, etc.

Everything else can go on mileage or measured wear.

Boofinator

  • Handlebar Stache
  • *****
  • Posts: 1432
Re: Owner's Manual Scheduled Maintenance - Time vs. Mileage?
« Reply #7 on: October 03, 2019, 07:16:14 AM »
Some things can go entirely on mileage,  most can't.

Any rubber item, lubricant or fluid of any kind needs to be replaced on a time schedule even on low mileage vehicles.

Rubber dries out and rots and fluids get contaminated by air, moisture and combustion byproducts and break down or lose their effectiveness.

That means oil, belts, hoses, tires, coolant, brake fluid, diff fluid, transmission fluid, etc.

Everything else can go on mileage or measured wear.

I don't disagree, but what mileage would you assign to these various components? My observation is that most of the owner's manual's recommendations are far too conservative and seem like a way to make a little more money for the service departments at the dealerships.

For example, I've owned my used-when-purchased vehicle for 15 years, and other than faithfully following the engine oil change guidelines (for mileage, not time), I've only changed out the brake fluid a couple times, the coolant once, the clutch fluid once, the spark plugs once, the air filter when needed, the battery when needed, and the tires as needed (twice, if I recall correctly). In this timeframe I have something like 130k miles on the vehicle, and nary a breakdown (except once for a dead (not discharged) battery). (I've been meaning to do my transmission and diff fluid, just haven't gotten around to it (my wife's automatic gets faithful tranny changes).)

BikingEngineer

  • 5 O'Clock Shadow
  • *
  • Posts: 23
Re: Owner's Manual Scheduled Maintenance - Time vs. Mileage?
« Reply #8 on: October 03, 2019, 10:26:00 AM »
To get a bit more into tires.... I agree with BikingEngineer that tires are probably the most important component of your vehicle, as they are your only connection to the road. However, where I disagree is in his strong position on replacing tires every 5-7 years.

The risks that people are willing to accept in life live upon a continuum. When it comes to tires, at one end of the continuum are people who would consider any degradation from performance at brand new as reason to replace their tires; by this logic, one should replace their tires after no more than three years, as that is when a statistically significant decrease in performance and strength can be measured (and if I was a racecar driver, I would follow this replacement advice). At the middle of the continuum falls NHTSA's advice, which requires tire manufacturers to test their tires following FMVSS 139, and based on a successful test advises that tires should be replaced after about 6 to 10 years (with earlier replacement advised for warmer climates). At the far end of the continuum lies my opinion, which observes that NHTSA's FMVSS 139 test is extremely harsh relative to how I drive, to include driving on aged tires for 24 hours at 75 mph, driving for 90 minutes at 75 mph on underinflated tires (20 psi for standard passenger tires) at full load, and driving at 100 mph for 90 minutes at standard pressure. Since I don't drive like a maniac anymore (per George Carlin's definition, https://www.youtube.com/watch?v=XWPCE2tTLZQ) and store my vehicle inside my garage for 95% of the time, I feel 10 years is the minimum amount of time I would use for replacement, and would probably go longer than that if my tread life hadn't been worn. (Obviously, any sidewall bubbles or other serious defects would call for earlier replacement.) Are my performance and reliability decreased relative to new tires? Sure, a bit. But by simply choosing to drive my car I've increased my risks of getting hurt or breaking down much more than by choosing to drive on tires that are less new than the standard by which tires are required to pass using a rather harsh test methodology.

Speaking of tread life, it is extremely important to replace tires if the wear bars are at 2/32", and I would even go 3/32" if I lived somewhere with regular torrential downpours. One hydroplaning event will cost you thousands of dollars and possibly your life.

References:

NHTSA Tire Aging Test Report: https://one.nhtsa.gov/DOT/NHTSA/NVS/Vehicle%20Research%20&%20Test%20Center%20(VRTC)/ca/capubs/811780.pdf

NHTSA test procedures for FMVSS 139: https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/tp-139-02.pdf
I'm actually mostly in agreement with you on this. A lot of it depends on your driving style, and your driving environment. If the car is parked indoors (as yours is), and is driven conservatively (as yours is) by a diligent driver (I'm assuming this applies to you as well) then a 10 year replacement cycle could be reasonable for a standard 70k mileage warranty tire. I generally recommend a slightly faster replacement interval, as I've noticed rubber hardening at the 4-5 year mark that would significantly increase stopping distance and compromise turning traction, even on a clean and dry road. Wet and hydroplaning traction is more dictated by tread depth and void space, and so is more dependent on overall wear rather than age. I'd rather err on the side of caution for something that is within my locus of control, and is so hugely important for the overall safety of the vehicle. That margin may let me stop or maneuver more quickly and confidently, and get me out of troubling situations, that to me is worth a few hundred dollars twice a decade.

MilesTeg

  • Handlebar Stache
  • *****
  • Posts: 1167
Re: Owner's Manual Scheduled Maintenance - Time vs. Mileage?
« Reply #9 on: October 03, 2019, 11:35:35 AM »
To get a bit more into tires.... I agree with BikingEngineer that tires are probably the most important component of your vehicle, as they are your only connection to the road. However, where I disagree is in his strong position on replacing tires every 5-7 years.

The risks that people are willing to accept in life live upon a continuum. When it comes to tires, at one end of the continuum are people who would consider any degradation from performance at brand new as reason to replace their tires; by this logic, one should replace their tires after no more than three years, as that is when a statistically significant decrease in performance and strength can be measured (and if I was a racecar driver, I would follow this replacement advice). At the middle of the continuum falls NHTSA's advice, which requires tire manufacturers to test their tires following FMVSS 139, and based on a successful test advises that tires should be replaced after about 6 to 10 years (with earlier replacement advised for warmer climates). At the far end of the continuum lies my opinion, which observes that NHTSA's FMVSS 139 test is extremely harsh relative to how I drive, to include driving on aged tires for 24 hours at 75 mph, driving for 90 minutes at 75 mph on underinflated tires (20 psi for standard passenger tires) at full load, and driving at 100 mph for 90 minutes at standard pressure. Since I don't drive like a maniac anymore (per George Carlin's definition, https://www.youtube.com/watch?v=XWPCE2tTLZQ) and store my vehicle inside my garage for 95% of the time, I feel 10 years is the minimum amount of time I would use for replacement, and would probably go longer than that if my tread life hadn't been worn. (Obviously, any sidewall bubbles or other serious defects would call for earlier replacement.) Are my performance and reliability decreased relative to new tires? Sure, a bit. But by simply choosing to drive my car I've increased my risks of getting hurt or breaking down much more than by choosing to drive on tires that are less new than the standard by which tires are required to pass using a rather harsh test methodology.

Speaking of tread life, it is extremely important to replace tires if the wear bars are at 2/32", and I would even go 3/32" if I lived somewhere with regular torrential downpours. One hydroplaning event will cost you thousands of dollars and possibly your life.

References:

NHTSA Tire Aging Test Report: https://one.nhtsa.gov/DOT/NHTSA/NVS/Vehicle%20Research%20&%20Test%20Center%20(VRTC)/ca/capubs/811780.pdf

NHTSA test procedures for FMVSS 139: https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/tp-139-02.pdf
I'm actually mostly in agreement with you on this. A lot of it depends on your driving style, and your driving environment. If the car is parked indoors (as yours is), and is driven conservatively (as yours is) by a diligent driver (I'm assuming this applies to you as well) then a 10 year replacement cycle could be reasonable for a standard 70k mileage warranty tire. I generally recommend a slightly faster replacement interval, as I've noticed rubber hardening at the 4-5 year mark that would significantly increase stopping distance and compromise turning traction, even on a clean and dry road. Wet and hydroplaning traction is more dictated by tread depth and void space, and so is more dependent on overall wear rather than age. I'd rather err on the side of caution for something that is within my locus of control, and is so hugely important for the overall safety of the vehicle. That margin may let me stop or maneuver more quickly and confidently, and get me out of troubling situations, that to me is worth a few hundred dollars twice a decade.

Trying to stretch a couple extra years out of a set of tiers falls squarely in "penny wise, pound foolish". Unlike trying to stretch out the life of say your transmission fluid, you aren't just risking damage to the vehicle, you are risking life and limb (as mentioned). If you can't afford, at a bare minimum, a 10 year replacement schedule then you can't afford to have a car. A $400 (installed) set of sedan size tires replaced every 7 years costs about $57 a year. $40 a year for 10 years. Over 20 years of car ownership, you'll save the purchase of one set of tires, or $400 ($20 a year). Not worth (financially or otherwise) the potential damage and/or injury or death that a rotted set of tires can cause.

You'll also find that most tire shops will refuse to work on a tire that is older than 7 years from the stamped date. That means no winter tire swaps, no puncture repairs, etc. Then you're in the position of having to buy a new set of tires on the spot, which is a good way to get ripped off (with cheap crap tires or overprices tires).

RWD

  • Magnum Stache
  • ******
  • Posts: 4232
  • Location: Mississippi
Re: Owner's Manual Scheduled Maintenance - Time vs. Mileage?
« Reply #10 on: October 03, 2019, 12:59:51 PM »
I do not go longer than 5-6 years on tires. Tires can look fine but then suddenly delaminate (tread separation) which can easily be fatal. Tires also lose performance as they age (the tires were 9 years old on the car that crashed and killed Paul Walker). I want my tires to be providing optimal grip for emergency braking and evasive maneuvers. Sure, tires can be fine up to 10 years but only in optimal conditions: keeping your car in a climate controlled garage, driving in a moderate climate, and not parking in the sun regularly.

I already lost one car due to cheaping out on tires, I learned my lesson.

secondcor521

  • Magnum Stache
  • ******
  • Posts: 3136
  • Age: 51
  • Location: Boise, Idaho
  • Big cattle, no hat.
    • Age of Eon - Overwatch player videos
Re: Owner's Manual Scheduled Maintenance - Time vs. Mileage?
« Reply #11 on: October 03, 2019, 02:13:59 PM »
The above posters are far more knowledgeable than me about cars.

My simple suggestions:

1.  Read and understand the original owner's manual for your car.  There should be a maintenance schedule in there.  If you have good reading comprehension, it will answer your question about miles or time.  Note that miles or time may be different for different maintenance items.

2.  Maintaining a car is a moderate hassle.  Repairing a car is a bigger hassle.

3.  Maintaining a car is usually pretty inexpensive.  Repairing a car is a waaaay bigger expense.

4.  If you do nothing else, maintain your tires (pressure, rotation) and your fluids (gas, oil, coolant, transmission, brake, power steering, wipers).

On tires, I'd suggest buying them from a place that will include rotations, pressure, and repairs.  I use Discount Tire, but Costco also does this.  Probably most tire stores do.  Discount Tire will adjust my pressure for me any time (I usually do it before road trips), and when they rotate them they'll give me a quick assessment on how the tires are holding up.

As a general note, you can put time/mileage reminders on your calendar.  For mileage items, what I do is put the reminder out about halfway to when I expect to have to do the thing.  Then when that date rolls around, I check my mileage and postpone again as needed.  Not the most beautiful planning process, but it works for me.

Finally, if you drive carefully and safely, your car will last longer.  Tires and brakes last a relatively long time for me because I don't peel out and slam on my brakes.  Aggressive driving not only costs more maintenance, it will eventually raise your insurance rates and may cost you your life.

ETA:  One other thing:  some model years and brands are better than others in terms of their ease of maintenance, and durability even under poor maintenance.  Personally I like Toyota/Lexus and have had good results with their products.  Ask around.  If you know a mechanic that you trust, ask them their opinion.
« Last Edit: October 03, 2019, 03:19:39 PM by secondcor521 »

Boofinator

  • Handlebar Stache
  • *****
  • Posts: 1432
Re: Owner's Manual Scheduled Maintenance - Time vs. Mileage?
« Reply #12 on: October 03, 2019, 03:07:09 PM »
I already lost one car due to cheaping out on tires, I learned my lesson.

I also totaled a car due to cheaping out on tires (hydroplaning on the interstate), and therefore take tread depth very seriously. That being said, was your's a hydroplaning event or another failure mode?

RWD

  • Magnum Stache
  • ******
  • Posts: 4232
  • Location: Mississippi
Re: Owner's Manual Scheduled Maintenance - Time vs. Mileage?
« Reply #13 on: October 03, 2019, 03:28:20 PM »
I already lost one car due to cheaping out on tires, I learned my lesson.

I also totaled a car due to cheaping out on tires (hydroplaning on the interstate), and therefore take tread depth very seriously. That being said, was your's a hydroplaning event or another failure mode?

Loss of rear traction on a wet road while taking a corner. I don't think it was hydroplaning as the road is slightly banked at that location. But I was not in the car at the time so it's hard for me to say for sure what the cause was. I had cheaped out by replacing just the front tires ~3 years prior to the accident. The rears were still the same as when I had bought the car, so at least 4 years old but probably quite a bit older.

JLee

  • Walrus Stache
  • *******
  • Posts: 6147
Re: Owner's Manual Scheduled Maintenance - Time vs. Mileage?
« Reply #14 on: October 03, 2019, 03:33:18 PM »
Mileage for almost everything*. The exception I would use is for brake fluid (tends to degrade more due to time than mileage) and of course tire pressures. For tires, I wouldn't exceed ten years from the date of manufacture (stamped on the sidewall) if the car is stored outside, though I would probably allow for double that if the car is stored under shade.

*Unless you (1) frequently drive for very short mileages, (2) spend a shit-ton of time idling, or (3) drive an insanely low number of miles. Note that 1 and 2 are antimustachian :(, whereas 3 is mustachian :).

I hope nobody is driving on 10+ year old tires...I don't go past five on mine. https://www.edmunds.com/car-maintenance/how-old-and-dangerous-are-your-tires.html

The tire compound hardens with age and loses grip and old tires can be downright dangerous.

Boofinator

  • Handlebar Stache
  • *****
  • Posts: 1432
Re: Owner's Manual Scheduled Maintenance - Time vs. Mileage?
« Reply #15 on: October 03, 2019, 03:57:14 PM »
I actually wrecked not one, but two cars in college due to hydroplaning in Florida. First was my RX7 (RIP), driving on I-275 on a perfectly straight stretch. The downpour began, I popped in the clutch to start coasting down, and then the next thing I knew the car was spinning like a top, fortunately only bouncing off the guard rails like a pinball game. Second was my 302 Crown Vic (ex-sheriff) purchased at auction following the totaling of the RX7; that car failed to take a right turn in the rain and plowed into some poor soul's SUV in Gainesville; thank goodness for PIT bumpers.

The common denominator to the two: I waited to buy tires until the first time I lost traction. Well, the first time was too late in both instances. Tread depth is real.

MilesTeg

  • Handlebar Stache
  • *****
  • Posts: 1167
Re: Owner's Manual Scheduled Maintenance - Time vs. Mileage?
« Reply #16 on: October 04, 2019, 10:54:44 AM »
I actually wrecked not one, but two cars in college due to hydroplaning in Florida. First was my RX7 (RIP), driving on I-275 on a perfectly straight stretch. The downpour began, I popped in the clutch to start coasting down, and then the next thing I knew the car was spinning like a top, fortunately only bouncing off the guard rails like a pinball game. Second was my 302 Crown Vic (ex-sheriff) purchased at auction following the totaling of the RX7; that car failed to take a right turn in the rain and plowed into some poor soul's SUV in Gainesville; thank goodness for PIT bumpers.

The common denominator to the two: I waited to buy tires until the first time I lost traction. Well, the first time was too late in both instances. Tread depth is real.

With respect, I don't understand the logic here of your posts. You seem to be lobbying to ignore guidelines on tire aging, yet you've experienced two accidents that, in your own words, were due to waiting for a tire to fail before replacing it rather than being proactive. Aged, hardened rubber doesn't necessarily increase the possibility of hydroplaning, but it does increase the probability of other traction loss failures in a tire even if it doesn't result in catastrophic failure of the tire.

Over the lifetime of tires and your vehicle, you're saving extremely little by trying to use a tire past 7 years and risking both large financial costs as well as life and limb. I just don't understand the line of thinking.

Boofinator

  • Handlebar Stache
  • *****
  • Posts: 1432
Re: Owner's Manual Scheduled Maintenance - Time vs. Mileage?
« Reply #17 on: October 04, 2019, 11:51:04 AM »
I actually wrecked not one, but two cars in college due to hydroplaning in Florida. First was my RX7 (RIP), driving on I-275 on a perfectly straight stretch. The downpour began, I popped in the clutch to start coasting down, and then the next thing I knew the car was spinning like a top, fortunately only bouncing off the guard rails like a pinball game. Second was my 302 Crown Vic (ex-sheriff) purchased at auction following the totaling of the RX7; that car failed to take a right turn in the rain and plowed into some poor soul's SUV in Gainesville; thank goodness for PIT bumpers.

The common denominator to the two: I waited to buy tires until the first time I lost traction. Well, the first time was too late in both instances. Tread depth is real.

With respect, I don't understand the logic here of your posts. You seem to be lobbying to ignore guidelines on tire aging, yet you've experienced two accidents that, in your own words, were due to waiting for a tire to fail before replacing it rather than being proactive. Aged, hardened rubber doesn't necessarily increase the possibility of hydroplaning, but it does increase the probability of other traction loss failures in a tire even if it doesn't result in catastrophic failure of the tire.

Over the lifetime of tires and your vehicle, you're saving extremely little by trying to use a tire past 7 years and risking both large financial costs as well as life and limb. I just don't understand the line of thinking.

The logic is that tread depth is extremely important, but tire age less so, depending on one's use profile. Additionally, the failure mode from hydroplaning is completely independent from any of the failure modes from tire aging, so any kind of conflation of the two failures should be avoided (other than that they both involve tires). I apologize if I seem to have conflated the two.

The use profile is very important, and I reflect that in how I purchase tires for my two motorized vehicles. For my motorcycle, I only purchase top-of-the-line tires (Michelin Pilots), as I occasionally try to eliminate my chicken strips with perhaps unwise driving styles. For my light truck (late '90s Ranger), I buy the cheapest tires money can buy, because I know for my truck that the tires will never be the limit for maneuverability (with perhaps the exception of an emergency braking event), and hence I'm a much more conservative driver.

Honestly, I've never had tires over ten years old, because they've always worn through their tread by then. However, I've worked as an automotive engineer in the Sonoran Desert where some tires on rarely used vehicles have been baking in the sun for over 40 years (I've seen tires stamped from the 1960's). Did these tires fail on a more regular basis than their younger brethren? Sure. Was this a risk our company was willing to take? Apparently (though I never asked upper management), because (a) it wasn't worth replacing tires every decade if they only put a couple of thousand miles on during that time with the only apparent wear being the dry rot and (b) these vehicles were driven conservatively, so any failures could be expected to be inconsequential.

What I will do is go back on my earlier comment suggesting over ten years is wise under some circumstances. Ten years from installation is probably a good limit for any vehicle that will be driven at modern highway speeds. For tires that have experienced considerable heat and sun, six years from installation might be a better limit.

BicycleB

  • Magnum Stache
  • ******
  • Posts: 2554
  • Location: Live Music Capital of the World
  • Older than the internet, but not wiser... yet
Re: Owner's Manual Scheduled Maintenance - Time vs. Mileage?
« Reply #18 on: October 04, 2019, 01:08:04 PM »
Appreciating this discussion very much. Posting so I can find it more easily.

FactorsOf2

  • 5 O'Clock Shadow
  • *
  • Posts: 25
Re: Owner's Manual Scheduled Maintenance - Time vs. Mileage?
« Reply #19 on: October 04, 2019, 01:32:21 PM »
Thank you to everyone who has weighed in so far. The tire discussion was very helpful; these tires are almost 6.5 years old at this point (warranty is 6 years) and down between 3 and 4 mm so we will be dealing with that ASAP. We do plan to keep a close eye on the pressure, not something we did with our previous poor abused car.

I finally figured out the correct term for googling this sort of thing is "maintenance for low mileage cars" which uncovered this other MMM thread that I'll leave for any other interested readers: https://forum.mrmoneymustache.com/ask-a-mustachian/car-maintenance-for-low-mileage-cars/

MilesTeg

  • Handlebar Stache
  • *****
  • Posts: 1167
Re: Owner's Manual Scheduled Maintenance - Time vs. Mileage?
« Reply #20 on: October 04, 2019, 03:03:29 PM »
Thank you to everyone who has weighed in so far. The tire discussion was very helpful; these tires are almost 6.5 years old at this point (warranty is 6 years) and down between 3 and 4 mm so we will be dealing with that ASAP. We do plan to keep a close eye on the pressure, not something we did with our previous poor abused car.

I finally figured out the correct term for googling this sort of thing is "maintenance for low mileage cars" which uncovered this other MMM thread that I'll leave for any other interested readers: https://forum.mrmoneymustache.com/ask-a-mustachian/car-maintenance-for-low-mileage-cars/

Oh, a very good point in that other thread: If you are irregularly driving the vehicle, a battery tender (a device that you attach to your battery to keep it charged up) is well worth the cost. That is, if you don't run it at least an hour or so a week on a regular basis. Lead-Acid batteries react very poorly to being drained, you want to keep them "topped off" as much as possible. If you prefer to not use a battery tender, make sure you drive the car regularly. Don't just idle it, drive it (lots of idling is bad).

Also good things to do:

1) Never let the gas tank sit for long periods of time below 3/4 full -- especially in winter months. Gas absorbs water from the air which causes it to degrade and turn to a sticky, viscous sludge (aka varnish) which clogs up fuel lines and injectors. More air in the gas tank means more air/water vapor.

2) This conflicts a bit with #1, but you also don't want to leave aging fuel in your vehicle as it will varnish with time no matter what you do. Best thing to do is run out all the gas in your tank at least every 6 months or so and fill up with a full fresh tank. Your road trips are a good opportunity for this. If I were you whenever I did a road trip I would use up nearly the entire tank before refilling. If you have to leave unused gas in the tank for more than 6 months or so, plan ahead and use a fuel stabilizer. https://www.goldeagle.com/product/sta-bil-fuel-stabilizer/ 

3) In general, don't let your car sit for more than a couple weeks without use, preferably no more than a week. Regular use keeps parts (especially internally lubricated parts) clean and helps prevent corrosion.