0W-40 instead of 5W-30?

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hotoil

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Our 1998 Toyota Camry V6 calls for 5W-30, and we've always used Mobil 1 5W-30. The car now has 121k miles, runs beautifully, and uses absolutely NO oil between changes every 4k miles.
Would there be any advantage to using 0W-40? A little "thinner" in winter and a little "thicker" in summer sounds like a good idea, but maybe not.
Your opinions?
 
Most toyotas call for a 40wt oil in many other parts of the world. Id be more comfortable using a 40wt in a toyota than in some other makes.

That said, how do UOAs look? Any need to improve? While in theory it may be better, why mess with success?
 
JHZR2-
Don't have the sheet in front of me, but latest UOA numbers are very good.
There is also a certain convenience in the fact that right now all three of our cars are using 5W-30. The other cars are under warranty, so I definitely will stay with the required 5W-30 for them.
 
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Originally Posted By: Smokescreen
A 0w-30 would be a better option. That way you keep the same weight you've had such great success with, yet improve winter startability.

About 5 years ago I spoke with one of the techs at Mobil, and I mentioned that their temp/vis graphs showed 5W and 0W as being the same down to the lowest part on the graph, about -20'F. He said that the 0W would only have an advantage below that temp, so the 0W would not be any advantage to me. Unless the graphs have changed, or it gets even colder here...
 
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If you want to try different oil to see if it would improve cold start in the winter but almost as thick at operating temperature, then M1 0W30 is worth a try. M1 0W40 is too thick for your car.

M1 10W30 - cSt @ 100º C 10.0
M1 5W30 - cSt @ 100º C 11.3
M1 0W30 - cSt @ 100º C 11.0
M1 0W40 - cSt @ 100º C 14.0
 
No advantage going to the 0W-40. I'd stay with 5W-30. As mentioned 0W-30 German Castrol is great stuff. I have pretty much settled in on SuperTech 5W-30 Synthetic.
 
you're running a really excellent oil, with exceptional cold properties, and ?why do you need a heavier hot viscosity. 30W is considered an ideal weight, and Mobil 1 is well ABOVE the minimum requirement for a 30W, which is a cSt of 9.3 - so I would say no - also a thinner viscosity cools the engine better, so I would not use the heavier oil, if anything, I would consider a lighter one, like a 0w30.
 
I second the Germal Castrol, not only is it a thicker 30 weight, it meets some really tough Euro standards (MB 229.5 and BMW LL-01). I'm using it in my Mercedes and Hyundai.
 
Where I work we carry a 0W40 oil but it is a DMO synthetic. I think in my engines (all over 150,000kms) it could clean it to the point of bad oil burning/consumption, with the higher amount of Detergent in DMO.
 
Originally Posted By: y2k345
Where I work we carry a 0W40 oil but it is a DMO synthetic. I think in my engines (all over 150,000kms) it could clean it to the point of bad oil burning/consumption, with the higher amount of Detergent in DMO.
DMO it that diesel motor oil? any way it will not clean to the point of bad oil burning etc. I would hope that with the maintenance done the engine would be spotless.
 
I really like that oil, 0W-40 M1, but I used it in a winter application in a Saturn thinking the low pour point (used to be -65F) would give better start-up economy and the thicker top end would protect better when I was running it on a work site and would reduce burning.

But I began to feel that it had an adverse effect on fuel economy and was thicker than I really needed...

I'd use Mobil1, Amsoil, or Castrol 0W-30...
 
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@Nickdfresh: I do use the M1 0W40 especially in my Maxima. From the UOA's I have seen GC30 (hard to find) seems to have slightly better Fe & Cu numbers. The Winter time I like using Valvoline synthetic 5W30. M1 0W40 did drop my MPG noticeably during Winter months.
 
If you want to go thicker and still be in the recommended range, you could
go MaxLife 5W-30. I believe that's available in a full synthetic version too.
 
If the engine has done fine with M1 5W-30, I think you've already found the right oil for it.
Yeah, you could try 0W-30, 0W-40 or GC, but it doesn't look like you have a problem in need of a soloution.
Be aware that both GC and M1 0W-40 have significantly higher HTHS than does M1 5W-30, so you might see some decline in fuel economy should you decide to try one of them.
Don't let the 0W fool you, either.
At the winter lows you'll typically see, neither GC, M1 0W-40 nor M1 AFE will be any thinner than M1 5W-30.
 
Seems that there is the 0w and the better pumping of the syn base oils and the 40 is on the lower end of the 40 visc range clost to the 30 range so give it a try. MPG drop during the winter ???? winter blend gas maybe. There would be a .01 mpg drop at the best if any give it a try. 4,000 miles on M1? oil Even if it is a so called sludger !!
 
M1 5-30 is an outstanding oil. If your engine calls for a 30wt oil, I would trust the engineers that designed your engine and use a 30Wt.
 
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