Lousy Mobil 1 warranty

Looks like we can ride it out. If it turns hard east we might drive across the state to friends on the east coast. We bailed for Irma 5 years ago but that was a biggie and we were “hurricane virgins”.

I don’t follow Toyota’s recommendations. They say every 10k miles. I’m not convinced 10k oil change intervals will keep my vehicle running o 300k miles (which is what we usually reach before buying a new one). So I change oil every 5k miles. That interval is good enough to keep at least 5 vehicles running well past 300k miles so I’m sticking with it.

Amsoil uses Viscosity Modifiers. I never understood the why people will buy this oil. It MAY be better. But how much better. I’ve had no problem keeping engines running without burning oil well past 300k miles. 2 even past 400k miles. If I use Amsoil then I should reach 1 million miles?

Or, as one of our departed members (Mountainbike) used to say…
The idea is to extend the life of the engine, not the motor oil.


Most of tne lower cost synthetics use group 3 oils because Castrol won a lawsuit Mobil filed on them claiming group 3 oils are true synthetics. Up to that point, Mobil used group 4 base stocks as did Amsoil. Group 4 base is more a true synthetic. To compete with “full synthetic” Castrol, Mobil 1 switched to mostly group 3 based formulations.

There are other oils that use group 4 base stocks. Some Mobil 1 products still do… 0W40 Euro spec Mobil 1 is one… and it is priced accordingly. LiquiMoly is another. The price is a good indicator… $25 for 5 qts is group 3, $35 to $40 is usually a group 4.

In reply to Tester (who I admire on this site):

The last time I read my car’s manual, the oil change interval was exactly the same for the entire life of the car. I believe my engines at 180K miles are much different from a new engine. And, I guess I am also sold on the hype that a full synthetic is better. Do any manuals discuss high-mileage oils? Unfortunately the car manufacturers and the oil manufacturers have somewhat competing goals

So, my non-scientific experiment has given the result that my 15 year-old Mazda 3 will be a quart low at 4000 miles, and my other 25 year-old cars will be a quart low at 2000 miles.

Still, based upon what I have read here, I will increase the frequency of my oil changes.

Now, I will ask everybody what they think of the 20,000 mile oil filter!

| Tester
September 26 |

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I’ll never understand why people follow an oil manufacturers recommended oil change interval and not the vehicle manufacturers recommended oil change interval?

I guess you would just have to take one of those filters apart. Of course in the old days you changed filters every other oil change,

I just use oem filters and change every time. I use ac on the Pontiac and change every 3000, and Honda on th Acura and change every 5000. Filters are no more than $5 and order a half dozen at a time. Works for me.

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A 20-k mlle oil filter is nonsense. you would never wait that long to change your oil. my daughters leased 2021 VW Tiguan says change the oil every 10k in her manual. I think that is crazy. and yes, she has the oil change interval meter that she goes by. If she owned the car, I would tell her to change the oil every 6k miles


Vehicle manufacturers only refer to synthetic oil in their owners manuals if it’s recommended, but I’ve never seen a reference to high mileage oil in an owners manual.

My car is pushing 230.000 miles. And the previous owner and now myself have used nothing but regular 5W 30 dino oil. But I’ve been using a high mileage oil for the past 4 years because of an oil leak at the front seal.

You can use an oil filter for 20,000 miles. But I don’t think it’s good idea.

Because oil filters have by-pass valves, and if the filter doesn’t, the engine does.

So, if you use an oil filter until the filter media becomes completely loaded with contaminates where oil can no longer pass thru media, it means you’re pumping contaminated oil thru the engine 100% of the time.



I have to disagree with the article that @Tester linked to. Oil in an unopened bottle will not degrade, but its additives might. I don’t know enough about the chemistry of modern oil to make that call. But the oil has been in the ground for millions of years and now someone wants to tell me that it will expire in five years.

Modern oils can withstand over 300 degrees F without any thermal breakdown, well above the air temp in my shed on the hottest day of the year. It does thicken when it get too cold, but it thins out when it warms up. Brand new oil does that.

To me, the greatest threat come from the oil specs. I would use old oil in an old engine, but if you use old oil in a new engine, the oil may not meet the correct specs required for the engine. I.e, if you found some old that was marked as meeting the specs for SM, that oil will have an additive that could shorten the life of the catalytic converter, so your vehicle may require that your oil is at least SN or SN+.

I have gone two or more years between oil changes in a vehicle that I only drove occasionally and always put at least ten miles on it everytime I started it (usually a lot more). It lasted well past 250k but it wasn’t the engine that put it in the junkyard. It ran perfectly and did not burn any oil. It was an F-350 driven by someone who just had to send a text at 55 mph.


It depends on what you mean by lax maintenance. We do what Honda recommends for our 2017 Accord and 2019 Odyssey. The OLM tells me when to change oil, typically about 10,000 miles when I eclipse 20% life left. I have other services like tire rotation done at the same time, along with air filter, tire, and other inspections. My tires wear evenly side to side and front to back. I have over 50,000 miles on the OEM tires and it looks to me that they have at least 10,000 miles left. The Odyssey has a maintenance minder and tells us the entire set of work required when it enunciates. I’ve used OLMs since 1998 and the engines always last close to 200,000 miles when I sell or trade. One thing I do more often than recommended is change the trans fluid at about 40,000 miles.


Between living 44 miles away from my workplace and having a son that plays baseball on a travel team, I drove 8,200 miles in 4 months this summer. Sounds like I should use Mobil 1. Oh wait, I already do. But I did change it before it was due. My oil life monitor indicated oil life at 20% at 8,200 miles, and the engine had used 2 qts of oil in that span.

Just about every manufacturer states that oil should be changed after 1 year regardless of mileage. That would certainly hold true no matter what oil you use.

Sure, Mobil will warranty your engine if you use their oil under their terms, but why not just use the oil your engine requires, change it according to the factory manual, and let your car warranty handle any issues. Why involve a third party?

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My guess, not much chance of harm to engine or oil b/c it is not replaced in more than a year. Warranty has time limit, lawyers required that so to minimize chance somebody will ask for warranty repair 10 years later; hard to find all the paperwork from that long ago.

I don’t recall anyone here posting about having to ever use the Mobile 1 warranty to repair damage to their car engine. You could use the forum search feature to verify, link upper right this page.

I own two vehicles, 30 and 50 years old, used only dinosaur oil (conventional Pennzoil) , changed w/filter every 5,000 miles, never had any oil-related problem. I think that method eliminates many of these issues entirely, a more common-sense approach, just my opinion is all. Best to always follow manufacturers recommendations for oil specs and replacement frequency.

I just changed this afternoon. 3050 miles and the monitor was at 38%. About 6 months. I checked the store for oil and they actually had four jugs of Dino so I bought one. The other shelf that has mobil1 is still almost empty yet. It’s been almost a year.

How many years does it take to accumulate 5,000 miles on your car or truck?

Truck has been daily driver the past three years, oil changes on it about every 6 months. Other routine stuff done too, like radiator repair, coolant replaced, brakes inspected and various brake parts replaced. On the other hand past 3 years, Corolla has been racking up zero miles per year. Remains off the road. Haven’t changed oil or filter on it in 3 years. I do check dipstick occasionally, level remains at top mark, & still clear. Only significant service on Corolla during Covid has been replacing leaky water pump & new coolant. Oh, and both vehicles still get the normal surface treatment, rinsing, washing, waxing.