I plan on purchasing a 09 SC/TC this sat, but Ive been driving my buddy's cobalt to get used to the size and blind spots on his car. He has a 08 Sport. The main thing that bothers me is his Tire pressure is always low because he is too lazy to fill them up the right way. His DIC says that each tire is at about 22-27 PSI

Ive bitched about it but he still hasnt done anything. About how many MPG do you think he is losing out on? His DIC also says he avgs about 21.9 MPG and he doesnt really drive that crazy, more grandma like than anything.

Never uses cruise control either...

 

idk what your looking for here butttt you just fill the tires up and they are good to go until it gets cold out or something. and he probably never resets the mpg so its not really all that accurate.

 

He's probably right, I reset my average every time I fill up, and even driving like an idiot sometimes I still manage to average 28+. Dude needs to get his tires to spec, and reset his mileage.

 

I was mostly looking for some possible numbers on the MPG hes missing... maybe I'll just steal his car and get his tires in spec...

 

Haha, yeah, those are city miles for me by the way, get the tires up to spec and reset that mileage. See what you get.

 

See what he gets you mean...

I'll prolly try and convince him to get some damn air in the tires this weekend. I'll let yall know what he ends up with if he ever gets around to it

 

It is more than just fuel mileage that is being lost there. Lowering the tire pressure by that much increases flex in the sidewall, weakening them over time and allowing them to flex enough to create more possibility of a blow out. On low profile tires such as what we're running sidewall roll and debeading isn't as big a possibility, but it still needs to be considered. Being that low also cuts the contact patch considerably, lowering control significantly.