If 0w-20 in the winter why not 5w30 in the summer

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So we all know that the industry is moving to 0w20 ... but if that is the right weight for a winter viscosity why would not a lightweight (energy conserving) 5w30 be just as suitable or better in the heat of summer.
 
You could do that, no problem. 0w-20 in September and 5w-30 in March. There is just really no need unless you are in the "Great White North". Both oils should do well under normal temp variations.
 
I still think 0-20 or 5-20 for the northern tier and Canada, 5-30 for mid America, and 10-30 for the Gulf Coast, AZ and NM are the optimal weights. One size does not fit all. Houston, TX and Fargo, ND have vastly different climates.
 
Originally Posted By: T-Stick
So we all know that the industry is moving to 0w20 ... but if that is the right weight for a winter viscosity why would not a lightweight (energy conserving) 5w30 be just as suitable or better in the heat of summer.


Because your engine is water cooled.

Now if you were going to the track or anything that calls for extended high HP output stepping to the
25% thicker 5w30 might be ideal.

Towing in the mountains..

Then again if your vehicle has Coolers for everything the thin oil works fine.. you only need to step up in viscosity if your oil temp is higher.

-20f in minnesota is alot different that 110f in phoenix.. when you are pushing your vehicle somewhat.
 
Originally Posted By: Rand
Because your engine is water cooled.


Correct. More to the point, your engine is water cooled, and air temperatures on the hottest of days is still not much more than half of the engine's operating temperature, an almost 100F delta. Unless there is a malfunction or design problem, that's a lot of latitude. I've seen electronics cooling systems where the deltas are 10F between operating and outside cooling. Now that's a challenge.
 
Originally Posted By: T-Stick
So we all know that the industry is moving to 0w20 ... but if that is the right weight for a winter viscosity why would not a lightweight (energy conserving) 5w30 be just as suitable or better in the heat of summer.


Why cant people accept that 0w20 is perfectly effective year around regardless of where you live, for daily driving?
 
0W-20 will be fine, so will 5W-30, in PA ( Pennsylvania? ) a 5W-30 Synthetic will do just fine too.
If your particular engine has some fancy VVT system though i would stay with 0W-20 as thesse systems tend to work based on oil pressure and don't work right with the wrong viscosity.
 
Originally Posted By: T-Stick
So we all know that the industry is moving to 0w20 ... but if that is the right weight for a winter viscosity why would not a lightweight (energy conserving) 5w30 be just as suitable or better in the heat of summer.


What vehicle / engine / use / driving style?

I'm running the same 0W-20 PPPP in my 5.7L Hemi with MDS in San Antonio summer I ran in winter when I lived in the Great Lakes area with no problems. I typically run 5W-20 in the warmer 6 months because I bought a LOT of QSUD 5W-20 when it was $0.99 / qt. after stacked rebates at Menards, then had trouble during a Polar Vortex winter that didn't reappear when using 0W-20 the following winter.

My engine oil is water cooled and automatic transmission fluid is air cooled, no thermostats on either oil cooler or transmission fluid cooler (extremely evident during winter when I was living in the Great Lakes area).
 
Originally Posted By: Rolla07
Originally Posted By: T-Stick
So we all know that the industry is moving to 0w20 ... but if that is the right weight for a winter viscosity why would not a lightweight (energy conserving) 5w30 be just as suitable or better in the heat of summer.


Why cant people accept that 0w20 is perfectly effective year around regardless of where you live, for daily driving?


Because there are much better options for wear protection and other lubrication dimensions, and a lot of people care about that?

That might be a reason.
 
Originally Posted By: T-Stick
So we all know that the industry is moving to 0w20 ... but if that is the right weight for a winter viscosity why would not a lightweight (energy conserving) 5w30 be just as suitable or better in the heat of summer.

You can, but OEM's won't.
It's about $$$......and CAFE penalty.
 
5W20 year round in my wife's CRV. Close to 170K trouble free miles. If it ain't broke don't fix it.
 
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The question is not posed for any particular vehicle, or for personal advice or for warranty considerations. The question is purely empirical. Most vehicle manuals recognize temperature ranges as part of the oil selection criteria even if they specify one recommended viscosity such 0w20. My point simply is that the viscosity of a 20 weight in winter temps of 0-10 degrees after the oil is warm cannot be that much different from the viscosity of a light 5w30 in 95-100 degree weather in the summer. The cooling system will usually not be able to completely uniform engine temps despite outside weather.

So my point is that if a heavy 20 weight is optimum for protection and performance, then probably a lightweight 5w30 is optimum in the heat of summer because 5w30 will often thin to a heavy 20 weight in hot temps while a 20 weight may thin more than what is optimum.
 
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It is a challenging topic. I was just reading the 17 ford focus uoa post. FF is 5-50 that thinned to a 30 I think.

There must be something different about the engine in that focus. Clearly Ford does not want 20 grade oil in that model.
 
Quote:
Why cant people accept that 0w20 is perfectly effective year around regardless of where you live, for daily driving?


Ignorance? I have 100k miles on my mazda3 with 0w-20, runs just as well as when I bought it new.
 
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Quote:
So my point is that if a heavy 20 weight is optimum for protection and performance, then probably a lightweight 5w30 is optimum in the heat of summer because 5w30 will often thin to a heavy 20 weight in hot temps while a 20 weight may thin more than what is optimum.


Do you believe ambient air temp affects a water cooled engine that much?
 
Originally Posted By: gfh77665
I still think 0-20 or 5-20 for the northern tier and Canada, 5-30 for mid America, and 10-30 for the Gulf Coast, AZ and NM are the optimal weights. One size does not fit all. Houston, TX and Fargo, ND have vastly different climates.

And xw-20 works well in both.

I was weary about using xw-20, but after seeing all the evidence here of excellent results in multiple climates and conditions with many different name brands, I have no problems using it in an engine spec'ed for it.
 
Originally Posted By: ozric
Quote:
Why cant people accept that 0w20 is perfectly effective year around regardless of where you live, for daily driving?


Ignorance? I have 100k miles on my mazda3 with 0w-20, runs just as well as when I bought it new.


I have put close to 400K on two engines using 0-20. Both engines perform like new. In fact I chose 0-20 over 30 or 40 wt oils for the benefits I see.
 
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