Downside of using 0W-40 v.s 5W-30?

[SR5]

Originally Posted By: steve20
if scooter is air cooled I would use the 0-40 grade. Liquid cooled 10-30 would be fine.
Steve


Yes I agree, when air cooled go thicker.

My air-cooled motorcycles started out on GTX 20W50, before I moved onto Pentite HPR30 (20W60).

My liquid cooled motorcycles could run on 10W40. But I will admit to using Edge 10W60 in them quite often.

OP, what engine size on the scooter ?
A small engine isn't that powerful, and too thick an oil may take some of that power away. But a 40 grade should be OK in most situations.

 

[fdcg27]

Yeah, you make a good point.
What SI engine younger than the oldest member here for which any given grade is recommended would be hurt by the use of a 0W-40?
I can't think of any.
Engines are just not all that sensitive to oil grades. If they were, you'd see dead cars everywhere.

 

[BrocLuno]

Exactly

 

[KL31]

I theorize that 0w40 is superior because the 5w30 is a "resource conserving" oil therefore fuel economy is put higher in priority. The 0w40 is the flagship oil that is focused on protection and start up pumpability. It's a thin 40 too so it services the absolute widest range of vehicles too.

I think resource conserving is a total joke because there are too many factors that affect emissions much more than an oil that saves 0.3 poofteenths of mpg.

 

[TiredTrucker]

Originally Posted By: steve20
if scooter is air cooled I would use the 0-40 grade. Liquid cooled 10-30 would be fine.
Steve


If that is the case, why wouldn't a 10w40 be fine as well? Same cold flow rating as the 10w30, right?