Synthetic Oil..color..longevity



They are not all the same. You need to use 5W-30 full synthetic that meets GM’s specification as listed above by @Cavell. It will state on the contain if it meets this spec.


The owners manual states several times to use motor oil that meets Dexos specifications;

Notice: Use only engine oil that is approved to the dexos™_
specification or an equivalent engine oil of the appropriate
viscosity grade. Engine oils approved to the dexos™
specification will show the dexos™ symbol on the container.
Failure to use the recommended engine oil or equivalent can
result in engine damage not covered by the vehicle warranty.
If you are unsure whether the oil is approved to the dexos™
specification, ask your service provider.

Mobil 1 for example has the Dexos symbol on the container.


I like Bing’s point above, and I also change my oil more frequently than the manual suggests, even though one uses synthetic. Both of my cars’ manuals state the oil must be changed every six months even if the mileage is not at the max recommended. By my math, the difference to have the dealer change the oil in the synthetic-using rig is about $20 more per change. So about $40 per year. If I wanted to search for a deal, I bet I could get it lower. I pay about $59 for a synth oil change, car wash and vac at Subaru. My Mechanic charges me about $40 to do an oil change on my conventional oil Highlander. (Which I happily pay because he has put my cars on lifts to check things for free numerous times).


No they don’t. In fact I owned 2 vehicles (2005 4runner and 1998 Pathfinder) that clearly stated in the owners manual that to keep the same oil change interval if using regular dino or synthetic.


Yes, they do;

Quote from the article: Toyota has been shifting its fleet to 10,000-mile oil change intervals using synthetic oil.

And: Mobil spokeswoman Kristen A. Hellmer. The company’s most advanced synthetic product (Mobil 1 Extended Performance) is guaranteed for 15,000 miles

Quote: If you are using synthetic oil, the interval between oil changes can be extended.

And the oil guys own warranty:

Quote: The Mobil 1 limited warranty is valid for 10,000 miles or your vehicle’s OEM recommended oil change interval, whichever is longer.

And Toyota’s comments:

10K change interval on engines spec’d for 0W20 synthetic, 5K for all others.

While your sample size of 2 vehicles is a valid data point, I did not state ALL oils nor ALL manufacturers so those 2 points don’t invalidate the claim. Clearly the 2 biggest players in each field do accept extended change intervals with synthetics.


In older vehicles where the recommended oil is conventional oil, they had not had extensive testing done by the manufacturer with synthetic oil. As a result their owners manual stated to follow the recommended intervals regardless of which oil is used. Oil manufacturers did not want to be responsible for anything that might happen to an engine during extended oil change intervals so they also had a warning on the can/bottle to not exceed their automobile’s manufacturers recommendation.

Now you are seeing longer intervals recommended for synthetic oil because the auto manufacturers have done extensive testing with synthetic oil.


Nothing but Mobil 1 full Synthetic for me. I always catch it on sale at walmart. The cost is a determining factor. But it provides “piece of mind” for me. They probably are all about the same.


Let 'em.

The first wants to sell me cars more frequently (and wants to have their vehicle on paper be more environmentally responsible… it’s the fed thing), the second wants me to know how “forever” and superior their oil is. Neither wants to pay for a new car for me when mine wears out.

The moment you begin to consider marketing statements as evidence, you start down a slippery slope.

Every 5,000 miles admittedly may no longer be technically necessary, but I sleep better changing my oil often.


No argument there. If it makes you sleep better at night, then I’m all for it. Change yours at 5K

But we direct people every day to look to their owners manuals for the maintenance schedule. The link to Toyota is that definitive piece of data we direct people to. The Mobil 1 warranty is a company putting its money where it puts its marketing.

The oil company has the incentive to sell you more oil, the manufacturer may have an incentive to sell you more cars but there is an incentive for them to be on the road a long time. And how many people have we suggested buy a Toyota because they run a very long time? Lots.

So really there is a disincentive for both companies to recommend extended oil change intervals.


Your point is well made. We do always direct the owner to the owner’s manual.
With oil changes, I’ve always felt the frequency is a minimum and preferred exceeding the recommendation, but that is admittedly an inconsistency.

The Mobile warranty? I don’t see where it really means anything. They really have zero risk there. It’s like a guarantee I gave a young friend/neighbor today. I helped him solve a simple car problem for free and told him “my work comes with a double-your-money-back guarantee”. Since I charged him nothing, the guarantee carried zero risk.


If the manufacturer specifies synthetic for the engine, use synthetic. And use the exact type specified; i.e. 0w-20 or whatever. Other than cost there is no penalty to changing the oil more frequently than the manufacturer recommends. Changing the oil and filter is pretty much the singular best thing an owner can do for their car, and can only help. Anything much over 5,000 miles between changes would start to make me nervous, independent of synthetic or dinosaur oil.


Using synthetic oil will not let you extend your oil change interval BEYOND WHAT YOUR OWNERS MANUAL SAYS. My Toyota call for 0W20 full synthetic and 10000 mile or ! year changes but says I can use conventional 5W20 if I can’t get the synthetic but change at 5000 or 6 months and put the synthetic in.

Of course it is your car and your money. It is your car, and if you are out of warranty. or don’t care about voiding your warranty you can use castor oil if you want.

Early race cars used castor oil because it was better than the petro oil at the time. It only had one tiny flaw. Once it was subjected to engine heat, it had to be removed immediately after the race because it would gel when it cooled.


If your goal is to make the oil last longer, go as long as you think you can on your synthetic.

If your goal is to make your engine last longer, go no farther between changes than the oil change recommendation in your owner’s manual. Or change it even more often than that.

My goal is always to make the engine last longer. Your goal is your choice.


Great back and forth discussion here. My GF’s 2013 BMW X3 (like all BMW’s I think) had no oil dipstick and would use an algorithm to calculate and advise when an “oil service” was required. She had it from new till about 55K miles. She went about 15K on the first change, and offered to pay for an oil change sooner when she was there before that for other reasons, BMW said “No.” We were back in a month to do it when the light came on.
Here is the short list of stuff that failed or broke:

  • The entire vehicle electrical system (opened the hatch on the highway, ran washer fluid pumps til it killed the battery, lit up all the idiot lights, then after she exited with her child, locked all four doors and would not allow them to be re-opened). It failed twice. Twice some kind of computer was replaced - not reprogrammed.
  • The Coolant disappeared from the overflow tank and lit up the idiot light. BMW refilled it with tap water as she watched.
  • The Brakes told the car they needed service at about 38K. BMW reset the warning light. Did not change brake pads or rotors. Light came back on at 51K, after included maintenance was up. No bake pad left.
  • The main controller (not a sensor) for the TPMS system failed.
    The engine was perfectly fine as far as we could tell, though a whining sound started at about 50 K. She traded it in recently. My point is that pretty much everything but the engine broke on that vehicle. I’m with George above. I don’t trust super-long oil “service” intervals. I would be cool with 10K on a car I only planned to own under warranty. I have to take the damn thing to a garage every year anyway to get the sticker in my state and I need to rotate the tires twice a year. An oil change only adds 15 minutes to that visit. I could care less about paying for the oil change. It is a teeny-tiny percentage of my cost of ownership. I do respect that for some the cost is important. Thanks for listening.


Sadly that kind of sounds like BMW electrical systems…but that dealership…wow…that’s horrifying


German engineering at its finest…


Yup. 2 different dealerships actually. We quit on the first one. We have a great local mechanic, and he actually owns an X3. He threw his hands up on it though and passed on servicing the TPMS system. That was a $600 hit. He correctly diagnosed it and did not charge us. He was the one who said, “The brake light went on at 38K and it needs brakes again at 51K?”


Well stopped by the dealership today and got documents showing all work done by dealership after car was traded in. It shows a oil change with synthetic 5W30 and dealership said the brand they use is darker then non synthetic oils. Still may get it changed. They also replaced the water pump, put four new tires on it and new brakes all the way around.


A friend has owned a series of BMWs. He says once you understand the shortcomings, you can take proactive steps to avoid problems. The water pump is plastic. After about four years, he replaces it with the equivalent racing pump. He uses the racing water pump because it is metal. He also replaces the washer fluid reservoir and coolant reservoir every few years because they will crack if he doesn’t. He does it early enough that there are no fluid losses. He like some the cars so much (5-series) that these extra steps don’t bother him.


The fact that he considers this acceptable in his cars suggests to me that he’s probably not a good reference source for your car purchases. His priorities are clearly not focused on reliability and longevity. He’s the perfect BMW customer. :smile: