Originally posted by Sage
Someone on GameFaqs once posted the exact specs for all of this stuff (break-in period, when you lose HP, etc.), but I'm not about to go searching through all of the junk there just to get that little bit of fairly unimportant info.
I did a search for the word "oil" in every FAQ on GameFaqs and didn't find this, and couldn't find anything on their forums, either. Nobody seems to have exact numbers. If you saw it somewhere, I think a lot of people would be happy if you could find it again...
I did figure out the exact numbers for HP. It's all based off the peak power of the car.
The max modifiers are
exactly:
-5.0% = dirty oil
-3.0% = not broken in
-2.0% = old engine
So, when you get a car, it has a -5% dirty oil modifier and a -3% not broken in modifier. These are compounded, not added. The final number is calculated as:
(peak HP) / 1.03 / 1.05.
The only problem is that peak HP isn't an integer, but what you see displayed is rounded off, so it's hard to tell what the actual HP is.
For example, the Miata LS has 168.3 peak HP, so it shows up as:
168 HP broken in with oil change
163 HP new with oil change (168.3 / 1.03 = 163.4)
160 HP broken in with dirty oil (168.3 / 1.05 = 160.3)
156 HP new with dirty oil (168.3 / 1.03 / 1.05 = 155.6)
You also have to remember that the numbers the car dealer shows are often wrong and you have to buy it and check your garage to make sure.