Hi fellas,

I'm from Australia and my EVO IX is due for $130k kms service first since I owned her, currently running Penrite 10W40 Full Synthetic. I love Mobil 1 & Royal Purple oils (used them on my STi) and I was wondering if I can still run the manufacturer recommended grade 5W30 although the car is mild modified (231kwaw). My mechanic said I have to use 10W40 since the car is modified as 5W30 and 0W40 are thinner so no good. I would like to use 0W40 since its going to be freezing cold as we heading to winter season in a few months time so will help a bit with cold start.

Please advise me guys,

Cheers

 

Yes, you can use 5w-30, but I would stick with the 40 weight oils for hard use. If you use Mobil 1 or Royal Purple, the M1 0w-40 or RP HPS 10w-40 are fine. Even with winter coming your way, the effective difference between a 0w-40 and 10w-40 is insignificant to you ... unless you've figured out a way to drive to Antarctica.

 

+1 to Ted.

The 40 at the end of each is the hot viscosity (cSt) range. An SAE 40 oil falls into a given cSt range at 100*C. The number before the W indicates the cold pour point. The lower the number the colder temp the oil can still flow (and I mean just barely flow, right before it becomes frozen solid).

At 100*C or thereabouts, close to your engines operating temp, any SAE40 oil will have similar viscosity (they are all SAE40 oils!), so the statement that the 5 & 0 W oils are 'too thin' is, quite frankly, BS. A 10w-40 is not significantly different at all at 100*C to a 0W-40 oil. SAE40 is SAE40. Want you want is an oil with a good additive pack. Mobil1 0W-40 is great, Penrite 10 Tenths racing 10W-40, Amsoil has a few suitable oils too. Unless you live where it gets sub zero, 10W/5W/0W aren't going to really matter to you.

 

0w40 is not thinner than 10w40 as said above. previously i used 10w40 motul 300v but have heard the change interval should be shorter as this is a pure race and over kill for daily drive (which my evo8 is). so now i currently use mobil 1 0w40. im not sure why US use 30weight, but most tuners i have spoken to say 40 weight is best for australia, esp when it heats up on some days.

i may try amsoil 5w40 next, or castrol 0w40

also another aussie

 

30 weight and now 20 weight is an effort to reduce friction losses due to viscosity when manufacturers are faced with ever stricter fuel economy goals (CAFE)

 

Thanks guys for all the inputs....I might look into M1 0W40 or HPS 10W40 and see how it goes.
Cheers

 

Also reducing things such as ZDDP content, to extend catalytic converter life and other emissions' equipment.... Mobil 1 10w-30 fits in those (CAFE) requirements,Mobil 0w-40 on the other hand is a performance oil.