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If my vehicle calls for 5-20 oil ,do you think my warranty would be void be my using 5-30 oil?
I guess I should ask the dealer, but some how I don,t trust the dealer. Thanks .

We just had this discussion here.


The owner’s manual will give some alternative oil weights based on the temperature where the car is driven. With 5W-20 oil readily available, your reason for using 5W-30 is what?

What I think doesn’t matter. If you have a warranty claim and the mfg feels improper oil caused the problem the warranty claim could be rejected. Is that possibility worth the risk? When the car is off warranty use all the 5W-30 you wish. Until the warranty period expires I’d stick with 5W-20.

Car makers know many cars will be sold in areas where summertime temperatures routinely go over 100 degrees…You must assume they know that 5w-20 oil will do the job at that temperature…But you should also know they will sacrifice engine life to meet a mileage standard…I would contact a company tech representative and ask them if using 5w-30 or 10w-30 voids the warranty…

My Odyssey calls for 5W-20, and I’ve had no problems with it. Honda engines tend to have very tight bearing clearances, and I think the V-TEC system may depend on oil pressure being within a certain range to work properly. Read your manual, and definitely don’t use anything above 5W-30. Using oil that is too thick can cause problems with the tight bearings found in Honda engines.

I believe the real question and the one that has to be answered first is:  

                                   Why are you asking?

Yeah…I was wondering that myself, but I didn’t ask. There is at least one discussion in here started by someone who put 20W-50 in a BMW “Because his dad has done that for 30 years”. He wondered why he was having trouble with the VANOS system.

Hmmm…On the basis of that reasoning (“Because his dad has done that for 30 years”), I guess that I should start putting straight 40-weight, non-detergent oil in my new car since my father used this type of oil in his '53 Plymouth.

Doubleclutch raised a conern that I too have wondered; what is the relationship between the current oil recommendations and the fact that oil is now being asked to operate variable valve timing systems as well as lubricate the engine and halp remove heat from the cylinders. I don’t know the answer, but I do know that it’s a good reason not to second-guess the guys who wrote the owner’s manual.

30 years? For me that’s almost yesterday. I have boots older than that.


Why are you asking? Is someone trying to tell you that you should use XYZ oil when the owner’s manual for your car recommends ABC oil? Or do you have a boat load of ABC oil in your basement or what?

Unless you have a reason to use an oil other than that recommended by the people who made your car, and likely know more about it than you and I together I suggest you use the recommend oil. Otherwise, I suggest you tell us “Why are you asking?”