How much longer does synthetic oil last?

I've got synthetic oil in my truck now and it's telling me it's time for an oil change. I'm tempted to reset the indicator and let it go again. After all isn't synthetic supposed to last much longer than regular oil?

Dad is using it in his Venture van. Lets the computer tell him when it is used up, then changes it. Usually about 5000 miles, depending upon temperature and driving conditions that the computer figures in.

Synthetic oil does last longer.Change the filter now and top off with a fresh qt.'They' they tell me synthetic will last 2-3 times longer than conventional oil.Change the filter at the 'regular' intervals.

Car computers are using whatever oil the manufactuer recommends to base its calculation of oil change intervals on. If synthetic is superior to the recommended oil ignore the computer and go by the oil manufactuers recommendations. If it is the recommended oil, change it.

My Tacoms manual says 5000 miles with dino oil...I been using synthetic and sticking with 5000.

The oil itself lasts longer; unfortunately it gets just as dirty.

The "on vehicle" oil life computers don't actually test the oil, they just use a math formula that considers cold starts, run time, engine temps and who knows what else to try and calculate when the oil should be changed.

The best way to find out is take a sample of your oil and send it in for analysis and you can work up your own oil change intervals based on specific needs.

Not sure, but what i do know is that european spec cars have oil change intervals of 12000 miles, while the same car in North America often has an oil change interval of 3000 miles. Why, i don't know. What i do know, is that the filter change is probably more important than the oil change.

Trucking co i worked for went from 15000 mile changes to 30000 mile 15 yearse ago . Oil was Castrol.. Analyis was always done on change. No problems

Not piston engine, but our Pratt & Whitney turboshafts are now no oil change for 6000 hrs.
We do ultra-sonic clean the reusable filters every 150 hrs. Pratt's reasoning is that by topping up the oil when low, we are actually changing it. Anyway, we use synthetic Aeroshell 560 and have no oil related problems with engines that run much hotter than an auto engine.
I use Mobil 1 in my pickup and Explorer and change at 5000 miles.

I saw a film made in Italy where a guy drove a Mercedes 200,000 miles on full syn oil. He then tore it down and the camera covered the internals. Wear was almost non existent. What it did have was a tan color to all the metal parts; not sludge, just a tan coating sort of like in a barbecue smoker the grills will have a thin smoke coating. Nothing else.

I change my oil once per year or if it looks like it's getting dirty. Seldom does. I run my lawn mowers all season on one oil change and it's still honey colored at the end of the season. Never could do that before. One of my mowers is 7 years old and I don't have to add any oil all season.

It works for me and that my friends is all that matters to me.

Mark

If it is a newer GM, I would not recommend it without at least spinning on a new filter and topping off the oil. The filters are very small, and they are having some cam/lifter problems due to the extended drain interval.

You don't say what make of vehicle you have, but GM spcifies "Dexos"-certified oil for 2011 and newer vehicles. In general, most full synthetic oils should meet Dexos, but some companies choose not to pay for Dexos certification.

The oil change indication seems to come on at about the same mileage on late model vehicles as with older models, so I think it's safe to say that GM doesn't think you can use a longer oil change interval just because you're using a better oil.

I use a gadget called lubricheck, it tests the oil, tells you when to change it. Still change the filters at the right interval. The gadget cost $40, my jury is still out on it, I check and double check, a week later.

I'm tempted to reset the indicator and let it go again.

I would not go their. GM has admitted their oil life indicators are wrong and resetting/reprogramming them ...

If you are buying the cheaper synthetics I would change at 5000. Otehrwise 7500 on a Mobil 1.

My new P/U is a Chev 4.8L. The warranty requires some fancy named oil that GM markets. Nobody will admit to it but I am betting it's at least synthetic blend. So I just go one step farther and use Mobil1 0w-30 since it exceeds the warranty requirements of the funny named 5w-30 required. But I still only change it once a year.

For what it's worth I know their ATF is pure syn and their diff. oil is too. Nowhere in the owners manual is ANY mention of changing either for the life of the maintenance record which I think is 150,000 miles.

However, I live in the country, every trip is at least 7 miles, I drive about 6000 miles per year, don't sit in traffic or pull heavy trailers very often and all that so really I fit in the once per year or 7500 mile upper limits of todays warranties with the better lubricants we have.

Mark

Sounds like CYA to me.

We put 8,000 miles on our Buick this winter, the computer said it still had 48% of it's life left. It was all highway driving in warmer climates so I didn't see a problem. The oil is GM's semi synthetic, installed at the dealer, cheaper than other shops around town, and they do a good wash job. When we got back we took it in for and oil change and they said there was also a recall to reprogram the computer, to recommend maximum mileage on the oil to be about 7,500 miles. GM has found if you run the oil to 0% they are finding wear at 100,000 and these engines should go 250,000. Makes sense to me!

I have been using synthetics since they came on the market ion the 80's. I always run it 120000 miles. Usually still clear when I change.I have now switched to Mobil 1 extended use oil and will change every 15000 . Usually have to add a quart about 9000. Never had an engine problem in any engine I used synthetic in,.

(quoted from post at 18:27:42 04/15/13) We put 8,000 miles on our Buick this winter, the computer said it still had 48% of it's life left. It was all highway driving in warmer climates so I didn't see a problem. The oil is GM's semi synthetic, installed at the dealer, cheaper than other shops around town, and they do a good wash job. When we got back we took it in for and oil change and they said there was also a recall to reprogram the computer, to recommend maximum mileage on the oil to be about 7,500 miles. GM has found if you run the oil to 0% they are finding wear at 100,000 and these engines should go 250,000. Makes sense to me!

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And that ware is major ware meaning its expensive to repair... Why would anyone go their is beyond me...

Depends on condition of engine... Good engine and yes you can go longer..

Depends on condition of engine... Good engine and yes you can go longer..

I run synthetic in my 03 Jetta diesel. I change it at 10,000 miles or so. I've had good luck so far - 380,000 miles and the engine's original except for timing belts.

120,000 miles?

Where sir did you learn that the new oil GM is requiring is synthetic blend? Their ads don't mention it, the containers don't mention it, my GM dealer doesn't know what it is. I suspected that since they mandated to keep the warranty the oil used in your vehicle had to be certified to whatever name they gave their new required oil.

Course I use full syn and don't worry about it. But my point is that the manufacturing OEMs are coming around to the fact that syn lubricants have a place in their products.......about time.

Any idea as to part of the WHY trucks are being sold nowadays with a 100,000 mile power train warranty? That's never been the case in all of history. Course, OEMs didn't load their trannys and differentials with syn oils either. I know Chrysler and GM do it (owner of both). Haven't been around Ford since '98 so I have no idea, but probably so.

I bought a Cummins powered farm tractor back in '07. I wanted to run Shell Rot T 5w-40 full syn in it....a B3.3NA. The reply I got was that my B3.3 would be tickled to have you run it. They said to wait till the end of the 300 hour initial drain period so that the rings and such will have had an opportunity to seat aka wear out (er ah in) a little.

Did you hear that? I have run into that before and if that doesn't mirror the fact that syn is a superior lubricant than that's your short stick. Your money, your equipment, your decision.

I'm convinced and just trying to help others realize what I realized years ago and have been benefiting from for many years. Nuf said. I don't know why I even think of participating in these kinds of discussions. Big waste of time. I guess I stated my real intent.

Mark

Their oil is called Dexos. The dealer knows about it. It's required, according to GM, in everything 2011 and newer.

Yea he knows about it but not what it is. I told them I was running Mobil 1 and if they had a problem with that tough luck. They just waved a freindly goodby to me.

Mark