I've been using 5W30 instead of the recommended 5W20 for a long time. Could this be contributing to oil burning?

There are many websites that recommended 5W-30 for my car, so I went with that and have been using it for a long time.

I just realized that the cap on the engine says 5W-20 or 0W-20.

My engine does tend to burn oil occasionally.

Could this be a contributor?

'05 Camry

Not likely


I’d worry more the engine isn’t being properly lubricated when it is warmed up. If the oil is too viscous it might not flow through the bearing clearances freely. I suppose there’s an off-chance too viscous oil might increase wear on the piston rings and result in more oil consumption, but that seems pretty unlikely to diy’er me. Let’s see what the pro’s think.

how much oil is it burning?
your viscosity choice is likely not your issue. Older cars burn oil. It’s just a part of life. Heck, even some newer cars burn oil, and the manufacturers say it is ok and acceptable. Just depends on how much oil it is burning.


That oil cap is for a newer car, your owner’s manual shows 5W-30.


5W30 is an energy-efficient oil which will protect most non-turbocharged engines adequately, even if a different viscosity is recommended by the manufacturer. I use 5W30 synthetic oil in every vehicle that I own, and haven’t noticed any oil consumption, leaks, or other issues.

One of my cars happens to be a 2005 Toyota Camry

My physical owner’s manual clearly lists 5W30 as the only recommended engine for all engine options for that model year

In my opinion, someone may have put the incorrect engine oil filler cap on your car at some point in time

I’m in the USA. Do you happen to be located somewhere else? Maybe other countries recommended a different engine oil for a 2005 Camry?

Please don’t take this personally . . . this is one of the reasons why you should have a physical owner’s manual for your car, so there can be no doubt as to what the specs are for your car . . . engine oil viscosity, crank case capacity, lug nut torque and so forth

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It could.

A 30 weight oil flows slower at temperature than a 20 weight oil.

This means when the engine is hot, the 30 weight oil will spend a longer time between the engine parts it’s trying to protect. This is called residence time.

Where as with the 20 weight oil, the residence time is shorter because it flows faster.

Oil not only lubricates engine components, it also cools those components as it flows thru them.

So the 20 weight oil also cools faster.

So, longer residence time means over heating of the oil, which causes thermal break down of the oil, and worn engine parts.


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Another “ya made me look” post.
07 Camry, 4 cylinder, cap 0W20/5W20.
Owners Manual same for 4 cylinder, V6 takes 5W30.
So yes, if your owners manual states 5W30, oil cap is from a different car.
My GFs 07 burns about one pint/5000 miles.
My truck takes 5w20, also takes, at most, one pint in 5000 miles.

Had a 2005 Camry. The oil is 5W-30. As mentioned, you have the wrong cap not the wrong oil viscosity!


2005 was when Toytoa had the major issue with oil consumption. I believe there was a recall. 5W30 didn’t cause this, but it might have made the problem slightly worse. They used loose piston rings. The oil ring gets stuck and won’t expand and fails to lubricate the cylinder wall properly. Oil sludge can contribute to this happening. One missed oil change could cause a build up that makes it get stuck. But it probably would get stuck anyway. 5W30 would leave more sludge than 10W30 or 5W20, so that could make it a little worse. Maybe with SAE 30 or an expensive oil like Mobil 1 Extended Performance synthetic 10W30 or 5W20 it wouldn’t have built up sludge and the ring wouldn’t have gotten stuck. But it is probably too late now. I don’t know if some additive can get the ring unstuck. You might be able to keep the problem from getting worse.

Thicker oil usually increases engine life.

If the cylinder is scored or the hone marks are worn away, then it needs an overhaul. Either a new short block or a rebuild at a machine shop. The cylinder head doesn’t need overhaul unless you’re past something huge like 300k miles.

The proper replacement parts use stronger piston rings like they 400k+ mile Toyotas from a few years prior had.

“interesting” advice there . . . :face_with_raised_eyebrow:

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