I know that stock recommendation is 10W-30 but what if your running 400+whp...?

 

Not an expert, but does it not depend on your ambient temp more than your power output? Unless you're running exceptionally hot or very very high rpm, the 10w40 should do it surely? I'm curious now...

 

I am not a rocket engineeer either but the WHP should not matter much. You should focus on the temperatures where you live. If you go with Shyntetic oil you should be fine no matter what kind of power you make.


Preferably Mobil one, but other known brands are good

my .2c

 

Stick with 10W30 unless you live in a very cold climate.

 

If you are suggesting that 10W30 will perform worse in the cold than 10W40, then you are incorrect.

For street use a synthetic 10w30 or 10w40 should be fine. If you live in a very cold climate (below -18 degrees Celcius/0 degrees Fahrenheit) then you can use a synthetic 5W30 during the winter. If you live in a very hot climate and/or are racing a lot, then a synthetic 20w50 is also an option.

l8r)

 

Sick with 10-30w i know plenty of people that have that amount and over and they run the same mobil oil that it comes with stock. There are a few sites that have tested these oils and mobil seems to always comes on top.

 

+1