Why do certain oils void your warranty?

Messages
3,542
Location
Colorado
GM says to use 5 or 10w30 in most of their car and trucks. Some Fords call for 5w20. If you use an oil not recommed for your perticuler engine it will void the warranty...why? Mobil 1 0w40 will protect as good or better in an LS1 V8 then 5w30 so why won't GM honnor the warranty with this oil in the engine? Fords owners book say any other oil then 5w20 will viod their warranty. If an oil will protect well why not keep the warranty in effect? GM, Ford, Dodge, and all the imports know that oil other the what is in the owners book does protect as good if not better in certain conditions.
 
Messages
3,695
Location
Chattanooga, TN
It will only void your warranty if they can prove that the oil used was, in fact, the cause of the failure. If you used the incorrect weight and they know it their first reaction will be to not honor the warranty and inform you the oil was the cause. However, 99% of the time the oil was not the cause and it will be up to you to prove that it was not the casue of the failure. You will win but it will drag on for possibly years and because of this long drawn out affair most people just use what is recommneded to avoid these warranty wars. the wrong oil (assuming it is the proper designation SL, SJ etc. and meets or exceeds the API guidelines) is rarely if ever the cause of engine failure,. Almost always it is something else because if it were the oil it most probably would occur over time and far beyond the warranty period.
 
Messages
903
Location
CA
I think the EPA gives them incentive to use the recommended oil. Kind of like someone holding a gun to your head and giving you incentive to hand over your wallet.
 

Chris B.

Thread starter
Messages
3,542
Location
Colorado
If I had a warranty claim with my Camaro and I took it in to the dealer with 0w40 or 15w50 in it and they asked my what weight oil was in it and I said I always use 10w30 could they really tell the difference?
 
Messages
6,388
Location
Washington St.
quote:
Originally posted by Chris B.: If I had a warranty claim with my Camaro and I took it in to the dealer with 0w40 or 15w50 in it and they asked my what weight oil was in it and I said I always use 10w30 could they really tell the difference?
The vehicle maker might ask you to document that you followed their "recommendations" for oil type and oil drain interval. If anyone has a so-called extended warranty, then they're bound by whatever is written into that contract. If they don't follow their part, they shouldn't expect the "extended warranty" underwriter to pay for claims. Ken
 
Messages
3,023
Location
USA-Michigan
First of all the cannot deny to fix your transmission under warranty if you used the incorrect engine oil. They cannot do that, its not legal. If you have an engine problem and they determine the cause is improper maintenance then you may be SOL no matter what oil you used, weather recommend or not. So it would be a good idea to be nice to the service manager and techs. If you come across as a AH, they might be inclined to look long and hard to make it costly for you. By and large the dealers are happy to help and often go out of there way to honor warranty's. Its the people who come into the dealer bitching and being arrogant that have the most problems. I am looking in my owners manual and I notice they are very careful not to say that using the wrong oil will void a warranty. They cannot void a warranty just because you use some product and that product had no bearing on anything that failed. There are dealers, salesman and others who like to intimidate car owners in following their advice be good or bad by claiming this or that will void your warranty. If any dealer tells you that, rest assured you are not dealing with an honest person or dealer.
 
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