As the title states, what kind of oil should I run for mostly city miles? I do lots of city miles/short trips/semi-aggressive driving....I currently run 5w-30 synthetic....will a thicker oil such as a 40wt benefit me with city miles? If not, then why? I do know the vq35 love thick oils...and a 40wt is still within spec since the owners manual says as long as it's above 0 degrees....it rarely dips below 40 degrees here in Cali....

 

I run 10W30 all year round in California.

IMO, 10W30 is preferable in city driving becoz the oil shears down to 5W eventually.

 

I know the european FSM says the VQ35 calls for 20w50....the internals of the european vq35 are the same as american vq35s right? What grade of oil is best for city miles?

 

You should be fine w/ a XW30 for mostly city driving, especially since GC is a thicker 30 weight. The Euro spec'd 20W50 is mostly for extended high speed driving in hot temps.

 

is the rule of thumb...

thicker oils = high speed driving in high climate?
thinner oils = stop & go driving and shorter trips?

ahhh...that kinda didnt make sense....but anybody know the general rule?

 

I used to have a 1973 Celica ST w/out overdrive (1:1 ratio 4th speed) w/ an undampened oil pressure gauge. This thing would cruise at 75 mph at around 4K rpm (not much different than my 28 year younger 5 speed). I recall in the summers travelling on the interstate and the pressure being at a certain point (don't quite recall exactly), but if I slowed down to slower speeds, the oil pressure would go up as the oil temperatures cooled.

At higher speeds/rpms, the higher the aero loads/oil operating temps.

 

nice info...anybody else got any?

 

Its more of your total distance between trips.

Once the oil heats up and the engine is at optimal operating temperature, it matters little on the type of oil used but rather your drain interval. So for example, Chunger only drive about 5 miles to work in his SC'ed 4th gen. He's worried about cold start protection since his temp gauge hardly moves by the time he gets to work. Therefore he runs 0w30

HKS sells their own brand of motor oil for performance applications at 5w40 because cold start is not an issue and race engines will be running in more extreme conditions and temperatures.

XwY
x= people worried about cold viscosity
y= people worried about hot viscosity

IIRC, short trips require shorter change intervals 3,750 miles vs. long trips 7,500 miles.

someone correct me if i'm wrong

 

good info larry....I'm planning to use 0w30 for my next change...I do alot of city driving with short trips as well...