Motor Oil Change Every Year

[lazurduy]

I drive my 1998 Jeep Grand Cherokee 4.0L about 3000 miles (5000 Km) each year. The odometer reads now 99000 miles and it is in real great shape.
The Owners Manual (18 years ago) specify Motor Oil Change every 6 months or 3K-7.5K (depending on driving conditions) whichever comes first. Oil quality has much improved in the last 18 years.
I do not think that I should change the Castrol GTX Mineral Oil that I have been using for years every 6 months.
Any comments/help please!!!
Luis

[HPstache]

You signed up here just to ask this question? Strange place to start. Anyway, I would have no problem changing my oil once a year if that was only 3,000 miles or so. Just make sure you arent losing oil by checking the dipstick once a month or so at the gas station while filling up (easy time to remember).

Now with this being said... this is certainly not a smartewt place to try and save money. Changing your oil at 6 months is good insurance.

[Cadman]

Actually, I'd argue conventional oil quality is worse off than it was 18 years ago. For one thing, the amount of ZDDP has been reduced to a level where those of us running flat tappet cams need to use an additive at each change; unfortunately that adds another 5 bucks each time.

For a daily driver, I think two changes a year is cheap insurance, especially when a $10 bill covers five quarts and a filter.

[Bateaux]

Put in Mobile One 15,000 mile synthetic.   It will stay cleaner and easily make it for 12 months.   Cost more but more convenient than two changes.

[Tester]

You signed up here just to ask this question? Strange place to start. Anyway, I would have no problem changing my oil once a year if that was only 3,000 miles or so. Just make sure you arent losing oil by checking the dipstick once a month or so at the gas station while filling up (easy time to remember).

Now with this being said... this is certainly not a smartewt place to try and save money. Changing your oil at 6 months is good insurance.

I might be wrong but you should check the dipstick after the engine was off for longer than 5 minutes, like more than 1 hour? That is if you want an accurate reading. I check it when I get a level parking spot, before starting the engine the first time in the day.

[chemistk]

You signed up here just to ask this question? Strange place to start. Anyway, I would have no problem changing my oil once a year if that was only 3,000 miles or so. Just make sure you arent losing oil by checking the dipstick once a month or so at the gas station while filling up (easy time to remember).

Now with this being said... this is certainly not a smartewt place to try and save money. Changing your oil at 6 months is good insurance.

I might be wrong but you should check the dipstick after the engine was off for longer than 5 minutes, like more than 1 hour? That is if you want an accurate reading. I check it when I get a level parking spot, before starting the engine the first time in the day.

You would be correct - that is ideal, but you would want to wait more like 15-20 minutes after the engine is off for the most accurate reading. Checking it at the gas station is still going to ballpark it for you and can key you into an issue early if you know what you're looking at.

To the OP - you should not go more than a year, at most between changes. 6 months at most if you live in a high humidity region or a region which gets cold winters. Over time, oil that has been sitting starts to pick up moisture which will begin to lower the pH (make it acidic) and break down the oil - damaging engine components over time. Modern oils have stabilizers which helps protect against this, "classic" oils do not. If you wanted the best results going forward, I would switch to a modern oil (full synthetic) by changing out the old stuff, replacing it with synthetic, and then replacing that after ~500 miles.

[HipGnosis]

Gear head here.
Dad and grandpa were professional auto mechanics.
I've had cars, pickups, hot rods and motorcycles.
I've worked on em all and rebuilt engines for a lot of em.
I'm a big believer in synthetic oil, but it's not appropriate (cost effective) for every one / every situation.  And to really get the most from it, you need to do multiple oil analyses.

I recommend you use Castrol GTX High Mileage synthetic blend motor oil (specifically formulated for vehicles with over 75,000 miles) w/ Jeep brand oil filters.
Change the oil every year, and the oil filter every 2 years.

[Reynolds531]

Check Bob is the oil guy forum. You're fine once a year, but gtx isn't well thought of there.