Author Topic: This One Simple Trick Will Increase Gas Mileage by 15%!!  (Read 26851 times)

KittyCat

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Re: This One Simple Trick Will Increase Gas Mileage by 15%!!
« Reply #100 on: August 18, 2015, 02:13:38 PM »
Just came in the say that I am amused by the click-bait, Buzzfeed-like title you have here :)

Digital Dogma

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Re: This One Simple Trick Will Increase Gas Mileage by 15%!!
« Reply #101 on: August 18, 2015, 02:21:34 PM »
Seriously?  Citation needed?  Do you people have anything between your ears?  What's safer, 10 cars moving in the same direction at 70mph, or 9 cars moving at 70 trying to dodge 1 going 54? 

And no, politically-driven speed limits have nothing to do with engineering-derived PSA limits on tires.  Exceeding one does not have anything to do with exceeding the other. 

Seriously, you guys are fucking with me, right?  There's no way you're this dumb.
Going 10 miles over the speed limit might have little to no consequence 99.999% of the time you drive, but it could mean the difference between a dead person and an injured person if you hit a pedestrian or cyclist.

Everyone I know has these little 'rules' they make up so they can break the law while driving, but the fact is that nobody else is under any obligation to follow other peoples made up rules. I stop at stop signs instead of rolling through them, does that make me dangerous, or does it make the person behind me who doesn't anticipate this dangerous?

Is someone trying to hypermile on the highway doing 50mph for 2 or 3mpg a bigger problem than someone trying to get to their destination 2 or 3 minutes quicker by speeding at 70mph while dodging slower vehicles? In the end its about the drivers priorities, and chances are they don't align with each-other.

But to address the topic - I'd rather save money on gas by driving a little slower and planning my trips to reduce wasted mileage than by altering my traction by pumping up the tires to max recommended PSI without a heavy load. If MPG were so important to me I'd probably just purchase a smaller/lighter/more efficient vehicle and sell my truck to reap the rewards. Maybe when I get a new job where I can call out during snow storms I'll ditch the 4X4, hope the electric car market really takes off between now and then!
« Last Edit: August 18, 2015, 02:23:23 PM by Digital Dogma »

KittyCat

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Re: This One Simple Trick Will Increase Gas Mileage by 15%!!
« Reply #102 on: August 18, 2015, 02:36:39 PM »
Everyone I know has these little 'rules' they make up so they can break the law while driving, but the fact is that nobody else is under any obligation to follow other peoples made up rules. I stop at stop signs instead of rolling through them, does that make me dangerous, or does it make the person behind me who doesn't anticipate this dangerous?
I'm annoyed when I see people rolling through stop signs. Yeah, that's almost everyone where I live. On the other hand, I am elated when someone does come to a full stop. I need something else to which to give my attention.

music lover

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Re: This One Simple Trick Will Increase Gas Mileage by 15%!!
« Reply #103 on: August 18, 2015, 03:37:23 PM »
Is someone trying to hypermile on the highway doing 50mph for 2 or 3mpg a bigger problem than someone trying to get to their destination 2 or 3 minutes quicker by speeding at 70mph while dodging slower vehicles? In the end its about the drivers priorities, and chances are they don't align with each-other.

If someone is going 50mph and everyone else is going 70, then the person going 50 is a problem for everyone else. Conversely, if everyone is going 50 and one person is going 70, then the person going 70 could be a problem, but not always. That's because everyone has to maneuver/change lanes to go around the car going 50, whereas the person travelling 70 doesn't make everyone else adjust for them...they can pass slower drives if they are in the slow lane and the faster driver is in the passing lane.

When you blame it on people wanting to get there 2 or 3 minutes faster, you're completely missing the point. Within reason, the safest speed on a highway is to be travelling close to the same speed as other drivers...not exactly the same speed because then you get the person in the left lane blocking traffic. But, if traffic in the left lane is going 2-3 mph faster than the right lane, traffic will move smoothly.

music lover

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Re: This One Simple Trick Will Increase Gas Mileage by 15%!!
« Reply #104 on: August 18, 2015, 03:47:40 PM »
Everyone I know has these little 'rules' they make up so they can break the law while driving, but the fact is that nobody else is under any obligation to follow other peoples made up rules. I stop at stop signs instead of rolling through them, does that make me dangerous, or does it make the person behind me who doesn't anticipate this dangerous?
I'm annoyed when I see people rolling through stop signs. Yeah, that's almost everyone where I live. On the other hand, I am elated when someone does come to a full stop. I need something else to which to give my attention.

Rolling through a stop sign is a non-issue if no one is coming, and also a waste of gas. In England, signs that say "give way" are more common than stop signs. People simply slowed down enough to ensure it was safe to proceed. But, then again, they are far better drivers than North America.

KittyCat

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Re: This One Simple Trick Will Increase Gas Mileage by 15%!!
« Reply #105 on: August 18, 2015, 04:29:24 PM »
Rolling through a stop sign is a non-issue if no one is coming, and also a waste of gas. In England, signs that say "give way" are more common than stop signs. People simply slowed down enough to ensure it was safe to proceed. But, then again, they are far better drivers than North America.
The problem is, people assume that no one is coming, and oftentimes do not bother checking before rolling, even at turns on t intersections. Perhaps your experiences have been different from mine, but I do not trust the drivers around the area where I am.

Joggernot

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Re: This One Simple Trick Will Increase Gas Mileage by 15%!!
« Reply #106 on: August 18, 2015, 04:45:10 PM »
AIUI: Manufacturers set tire pressure for ride comfort, not fuel economy.  I have run max sidewall pressure on two vehicles (car and pickup) for many years with no problem.  Max sidewall is not recommended by me.

music lover

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Re: This One Simple Trick Will Increase Gas Mileage by 15%!!
« Reply #107 on: August 18, 2015, 05:03:30 PM »
AIUI: Manufacturers set tire pressure for ride comfort, not fuel economy.  I have run max sidewall pressure on two vehicles (car and pickup) for many years with no problem.  Max sidewall is not recommended by me.

They set tire pressure for both comfort and fuel economy, and I'm pretty sure the techs working at major auto manufacturers have a pretty good idea what they're doing. The people that made the tire set the maximum recommended pressure, but any particular tire can end up on dozens of different vehicles, which is why the car comes with a sticker that has a different recommended pressure.

Nubs

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Re: This One Simple Trick Will Increase Gas Mileage by 15%!!
« Reply #108 on: August 18, 2015, 05:11:26 PM »
Yeah,  I know,  funny huh?

So I checked my tires on the 1999 Mercury Mountaineer.  Damn 32 lbs!   Max inflate rated at 44 lbs.   I filled those babies up to 46 lbs.

Took daughter home to her moms house which is about 45 miles at 32 lbs and MPG 18.5 (I have a digital tracker)   Filled up the air.   Return trip 21.4 MPG.

That is a 15% increase in MPG!  Our annual car gas bill for 2 cars runs about $2,400 (yeah, I know I'm researching higher MPG cars)   So this little trick will save us $400 per year if we do nothing different. 

So yeah,   check your tires and don't be shy about going a tad over the max inflate.    By the way,  hypermilers increase their Prius mileage to 65 mpg simply by overinflating a tad.  Bike riders take note as well --- you could be peddling with 15% less effort. 


YMMV!

I don't do too much peddling on my bike, but I do like the sound of using 15% less effort when I pedal home tonight. . . or going faster.  ( :

The_Dude

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Re: This One Simple Trick Will Increase Gas Mileage by 15%!!
« Reply #109 on: August 18, 2015, 05:13:48 PM »
Just thought I would throw out my own anecdotal report.

Back around 2000 I ran a set of BFG KDW tires (255 width) at 44 PSI and it killed them much faster than when I ran the next set at 35 PSI.  The set ran at 44 PSI all went bald in the middle 1/3 of the tire and lasted between about 66% of the next set of tires. 

To me the moral of the story is that is greatly depends on the type of the tire (and I imagine width) on how much, if any, extra wear in the center is created by over inflation. 

Oh, one more anecdotal story since it was brought up earlier.  I am an active autocrosser.  My current tire of choice is the Falken Azenis tire which is known for a super stiff sidewall.  I run these tires much LOWER for maximum cornering grip.  I'm not disputing that many autocrossers inflate their tires above the recommended 35 PSI for maximum grip, but again, it depends on the tire. 

Bob W

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Re: This One Simple Trick Will Increase Gas Mileage by 15%!!
« Reply #110 on: August 19, 2015, 08:31:54 AM »
GM based its initial recommendation for my Volt's tires on the 35psi used for the Cruze, because the platform was the same. The additional 900# added by the battery and other novel powertrain components somehow totally escaped their consideration throughout the design and testing phases.

Early Volt drivers found that the recommended pressure produced a high rate of classic underinflation symptoms, including cracked and pitted sidewalls, edge wear, and frequent blowouts. Not surprisingly, increasing the pressure to 40-45 psi evened out the treadwear and reduced catastrophic events. Empirical testing by one pair of owners indicates that 49psi on the more heavily loaded front and 45 on the slightly lighter rear actually produces the most even treadwear.

GM, in response, increased the recommended pressure by about 2psi. Why so little? Community consensus is that they're unwilling to admit to having been so wrong. Look at the recent recalls, and tell me OEMs are never wrong.

Just food for thought. I'm not advocating exceeding the tire's limits, but I don't think anyone here is.

Thanks for that --- I'm really surprised at the number of hyperbolic negative responses here.   In a world were virtually everyone I know consistently exceeds the speed limit by 10% (maximum "legal" speed) it is as if I committed a crime and am endangering everyone on the road by maxing out my tires on my 4,000 pound vehicle.     Yeah,  I'll switch it out to a much more fuel efficient car someday.  And then I'll max the tires out on that car as well.

And yes 15% was my personal tested amount on that particular day.   (thanks to the posters who enjoyed my click bait!) I haven't bothered to further test as that was a pretty good indicator run day. 

So far one of my tires has worn more so on the inside of the tread.  While you might think this is a bad thing, when I bought the truck all 4 were worn on the inside.  My friend owned the truck for 10 or 11 years and always had this issue with the all wheel drive Mountaineer.   So it appears that my tread wear has actually improved.    Most of the sites I referenced indicated that in general tread wear is less with high inflation.  That makes sense as there is less flexing of the rubber.

I have put maybe 5-6K on the truck since starting this and haven't had any handling issue or dangerous stops in that time.  As I say,  I always try to anticipate stops well ahead and an increase in stopping distance appears to be the primary negative mentioned on the tire sites.   I have noticed,  and perhaps I'm wrong,  that I need or want to drive much slower on rocky bumpy roads.  That is about 5% of my summer time driving. 

I'm going to use one more trick and have that worn tire reversed on the rim.   Please don't beat me up over that. 

Ashyukun

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Re: This One Simple Trick Will Increase Gas Mileage by 15%!!
« Reply #111 on: August 19, 2015, 09:21:50 AM »
I don't do too much peddling on my bike, but I do like the sound of using 15% less effort when I pedal home tonight. . . or going faster.  ( :
The thing with bike tires, like many people with car tires, is that they're often not properly inflated even to what is recommended. On my road bike, that's between 90-100 psi, which I have to top off every weekend to keep up in the optimal range. There is a DISTINCT difference in ease of riding when they're properly inflated, though also a distinct roughness of the ride on my old solid-frame racing bike.

Quote from: Bob W
I'm going to use one more trick and have that worn tire reversed on the rim.   Please don't beat me up over that. 

As long as they're not directional-tread tires, there's nothing at all wrong with that. Correcting the alignment/inflation that caused it in the first place would be better (;P) , but that is a trick that auto-xers will use to extend the life of tires that wear very unevenly due to high cornering loads and it works well enough as long as there's not damage to the underlying structure of the tire.

GuitarStv

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Re: This One Simple Trick Will Increase Gas Mileage by 15%!!
« Reply #112 on: August 19, 2015, 10:13:06 AM »
I don't do too much peddling on my bike, but I do like the sound of using 15% less effort when I pedal home tonight. . . or going faster.  ( :
The thing with bike tires, like many people with car tires, is that they're often not properly inflated even to what is recommended. On my road bike, that's between 90-100 psi, which I have to top off every weekend to keep up in the optimal range. There is a DISTINCT difference in ease of riding when they're properly inflated, though also a distinct roughness of the ride on my old solid-frame racing bike.

Real recommended tire pressure depends on rider weight, type of riding, and tire size.  The front and rear tires should never be pumped to the same number.  The rear tire of a 250 lb man on an upright bike requires much higher pressures than the rear tire of a 90 lb woman on a road bike, even assuming they're using the same brand, model, and width.  The number on the casing doesn't really have anything to do with the pressure you should ride at.

As as been mentioned further up thread somewhere, it's also possible to inflate bike tires beyond where there's any real advantage regarding rolling efficiency.

Guses

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Re: This One Simple Trick Will Increase Gas Mileage by 15%!!
« Reply #113 on: August 19, 2015, 10:35:38 AM »
AIUI: Manufacturers set tire pressure for ride comfort, not fuel economy.  I have run max sidewall pressure on two vehicles (car and pickup) for many years with no problem.  Max sidewall is not recommended by me.

They set tire pressure for both comfort and fuel economy, and I'm pretty sure the techs working at major auto manufacturers have a pretty good idea what they're doing. The people that made the tire set the maximum recommended pressure, but any particular tire can end up on dozens of different vehicles, which is why the car comes with a sticker that has a different recommended pressure.

Scroll to my post somewhere in the middle of the 2nd page. I provide a link to an engineer that actually worked in the tire business. He states that the max sidewall pressure is not the "danger zone not to be exceeded" and that tires are not at a danger to explode unless you exceed the psi by multiples of the max recommendation. Increasing the pressure over the max sidewall point is just giving you less comfort for less rolling resistance.

Those claiming that it is unsafe should consider that low rolling resistance tires are exactly the same as overinflating a tire by a few psi. Low rolling resistance = less grippy tires. Blowouts related to overinflation by a few PSI are a myth.

The "safety aspect" is really a red herring. If you believe this, you should also advocate for much lower speed limits. Consider this: the difference in stopping distance comparing one car with max spec inflation tire versus the same care with max specs inflation +5 psi is laughably small. On the other hand going 5 MPH faster significantly increases stopping distance.

I am too lazy to link a graph, but a quick google will show you that the relationship is exponential.

« Last Edit: August 19, 2015, 10:39:17 AM by Guses »

Bob W

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Re: This One Simple Trick Will Increase Gas Mileage by 15%!!
« Reply #114 on: August 19, 2015, 11:00:29 AM »
AIUI: Manufacturers set tire pressure for ride comfort, not fuel economy.  I have run max sidewall pressure on two vehicles (car and pickup) for many years with no problem.  Max sidewall is not recommended by me.

They set tire pressure for both comfort and fuel economy, and I'm pretty sure the techs working at major auto manufacturers have a pretty good idea what they're doing. The people that made the tire set the maximum recommended pressure, but any particular tire can end up on dozens of different vehicles, which is why the car comes with a sticker that has a different recommended pressure.

Scroll to my post somewhere in the middle of the 2nd page. I provide a link to an engineer that actually worked in the tire business. He states that the max sidewall pressure is not the "danger zone not to be exceeded" and that tires are not at a danger to explode unless you exceed the psi by multiples of the max recommendation. Increasing the pressure over the max sidewall point is just giving you less comfort for less rolling resistance.

Those claiming that it is unsafe should consider that low rolling resistance tires are exactly the same as overinflating a tire by a few psi. Low rolling resistance = less grippy tires. Blowouts related to overinflation by a few PSI are a myth.

The "safety aspect" is really a red herring. If you believe this, you should also advocate for much lower speed limits. Consider this: the difference in stopping distance comparing one car with max spec inflation tire versus the same care with max specs inflation +5 psi is laughably small. On the other hand going 5 MPH faster significantly increases stopping distance.

I am too lazy to link a graph, but a quick google will show you that the relationship is exponential.

All true.  You would think that there would be a national push for over inflation.   Can you imagine the impact a 10% reduction in gas usage would have on the economy?  It is not a small thing.  Take the $400 per year we will save and multiply by 150 million and your looking at a 60 billion dollars "one simple trick."