Do I have to use 0w-40? - Smart Car of America Forums : Smart Car Forum

earldahl · 06-16-2009, 10:25 AM

Do I have to use 0w-40? A friend of mine said i could use 5w-30 but i'm not sure

SubSlr88 · 06-16-2009, 10:49 AM

I think I'd go with the 5w-40 if you can find it, rather then the 5w-30. That's about all I can find here in FL. . . haven't seen any 0w-40 in any brand yet, but the 5w is available most everywhere.
Since you're not in a sub-freezing area it should suit you well. And it's a recommended weight by smart, too.

chieftmc · 06-16-2009, 11:01 AM

Quote:

Originally Posted by earldahl

Do I have to use 0w-40? A friend of mine said i could use 5w-30 but i'm not sure

Food for thought: Motor Oil Viscosity

**jwight** · 06-16-2009, 11:37 AM

FWIW, I thought about going to 5W30 for the extra 2% fuel economy mentioned by Old Smart. However, our low temps here in the winter seem to weigh against that. Texas might be another matter.

Wdhitch · 06-16-2009, 12:02 PM

Quote:

Originally Posted by SubSlr88

I think I'd go with the 5w-40 if you can find it, rather then the 5w-30. That's about all I can find here in FL. . . haven't seen any 0w-40 in any brand yet, but the 5w is available most everywhere.
Since you're not in a sub-freezing area it should suit you well. And it's a recommended weight by smart, too.

Advance Auto Parts has it the 0w-40.... though I'm think of switching back to the 5w-30.

Old smart · 06-16-2009, 01:38 PM

Quote:

Originally Posted by earldahl

Do I have to use 0w-40? A friend of mine said i could use 5w-30 but i'm not sure

No. It is true that smartUSA has been using only 0W-40 for the VPC oil changes, but that is because the cars are then distributed to every climate in the country, a "one-size-fits-all" that may not be optimal everywhere. Refer to pg. 315 of your Operators Manual, which says "Using the chart below, select the oil viscosity according to the lowest air temperature expected befroe the next oil change."** Or, use the viscosity that competent service managers in your climate recommend.

** The '09, N.A. OpMan does not explain why the viscosity chart has been modified to truncate the upper range of 30-weights - the Euro manual doesn't, M-B doesn't, nor any other viscosity chart I can find. I'm not above believing that it is a smartUSA (Penske) subterfuge to lead people to shy away from common 30-weights in favor of less common 40-weights (just so happens that Mobil 1 0W-40 is readily found).

msjohnson1974 · 06-16-2009, 02:15 PM

Quote:

Originally Posted by Old smart

Refer to pg. 315 of your Operators Manual, which says "Using the chart below, select the oil viscosity according to the lowest air temperature expected befroe the next oil change."** Or, use the viscosity that competent service managers in your climate recommend.

Wait, your manual has a page on oil viscosity? Mine said refer to the dealer...