Liquidx02

Hey guys im running 10w40 non synthetic. Lately ive had people telling to me switch to 10w30. Can anyone explain why I would this?

Compression tests have me at 300 psi in all cylinders

Here is my setup
pr3 head ported and polished
JUN III cams and JUN valvesprings with crower titanium retainers.
B18C1 block with ctr pistons.

EPGONZALEZ

actually...10w30 is rec. by manufacturer if you dont live in cold climates...
if your car sees freezin temps...you want some 5w30

JSIR

in a non synthetic oil 10-40 could be the worst possible oil to use. The spread from 10 to 40 is 30 points. In order to get that wider srpead they have to use more additives to thicken the oil as it heats up, as the addtives wear out you are left with a poorer oil. The 10-30 oil has less of a spread and requires less additives, thus you get better protection as the oil is used with time. The 10-30 provides best protection IMO, the base oil is thicker than a 5-30 oil which should help. Now a 20-50 oil has a 30 point spread to it, but it starts with a much thicker oil base and does not require as many additives as say a 10-40, but it is too thick IMO and not necessary for daily driving. . hth.

nsxtcjr

Which means 5W30 for most ITR's. Just like it says in your owner's manual (where you can see the temperature chart).

BlazinITR

I use 10W30, because I burn through 5w30 in two weeks of driving.
that VTEC!

nfn15037

I hear that

DutchITR1689

FYI. 5W40 is recomended here in by Honda Europe.....

JSIR

5w-40 may be fine in Europe as it is most likely a semi-synthetic product, in which case they can engineer to oil to work better, plus you are most likely talking about a hot climate. In N. America Honda is now pushing use of 5w-20 oil, personally I don't trust that ****, but it may be fine. In a fully synthetic oil even a 5w-50 is fine to use, I usually put that in for track days. For daily driving I like a 10w-30 regular oil, or semi-synthetic such as Castrol. I don't drive it much in winter though.

Joey

SnyperSiR

Hmmm... I'm currently using 5w30 for the winter, but when it gets warmer, I'm considering 10w40 or 10w30, all synth of course. At one point the car was blowing blue and consuming a lot of oil so tried Mobil 15w50; any thoughts on that? It remedied the blueness and oil consumption was much better. At one point I tried Amsoil 0w40; car felt smoother than Mobil 5w30, but could be just psychological; any comments here?

*sigh* Time to do that engine flush; over 75K on a '00 model with oil services that come later than expected can't be good.