Changing Oil Grade

[T4RUNNER02]

Should the grade of the oil be changed at any particular milage? I currently use Mobil 1 5W30 with milage at 30,000. Is there a milage where I should consider a switch to 10 W30? If climate is a consideration, I am in South Florida.

 

[Sac State]

Apparently anytime. Everytime I have my dealer change the oil they use a different weight, both 5 & 10/30. The owners book says use 5/30, dealer says 10/30 is fine since we don't live 'up North'. In my case, I see the weight difference as a sludge factor. Toy engines are notorious for sludge buildup and Toy always tries to blame the fault on wrong oil weight or lack of frequent change.

I just change mine every 3K and I don't sweat it.

 

[Larry]

You should use the viscosity oil the owner's manual calls for. In the case of my V8 4Runner it's 5w-30. The only time you should consider a lighter weight oil is when it's rabbit a$$ cold. The only time you should consider a heaver weight oil is when your engine gets a lot of miles on it and starts to burn more oil. Until then go by the owner's manual. Don't let the dealer or anyone else put 10w-30 in your car if 5w-30 is called for. Don't listen to others, read the owner's manual. If the dealer says, 'We have local knowledge and we use 10w-30 in place of 5w-40", go somewhere else. Believe me, the factory knows more about your Toyota than a service manager at a dealership, trust me.

I have an 84 Civic that has 376k miles on it. It started with 5w-30 and gradually stepped up through 10w-40 (about 200k), 15w-40, and at 350k miles it got 20w-50. I based it on oil consumption over 5k miles. When it approached 2 quarts I upped the viscosity. The original oil consumption was under a half quart/1k miles.

 

[NoSpeedLmt]

I would stick to what the manual says. I had a Toyota Pickup '88 with 176k miles when I sold her to a friend. Engine was perfect, just needed a new clutch.

I have an 84 Civic that has 376k miles on it.

That has to be some kind of record. 376k miles, WOW!!!

 

[Bluto]

I have an 84 Civic that has 376k miles on it. It started with 5w-30 and gradually stepped up through 10w-40 (about 200k), 15w-40, and at 350k miles it got 20w-50. I based it on oil consumption over 5k miles. When it approached 2 quarts I upped the viscosity. The original oil consumption was under a half quart/1k miles.

So if you started at 10w-30, and not 5w-30, what would of happened

 

[Larry]

5w-30 and 10w-30 are the both just 30 weight oil. The 'w' stands for Winter and has to do with cold pumping ability of the oil. I live in Southern California. This car has never seen snow or freezing weather, so to answer your question, probably no difference at all. In 21 years this car may have seen a dozen days below 40F and never 32F or below, but plenty of days above 100F. In any case if the manual says 5w-30 for your new car just do it.