Originally Posted by Darth_Focus
I have the handling package. But, an 18" summer rated hard sidewall, low profile tire will no doubt offer less rolling resistance than other setups. That should aid in mileage unless the rims are made of cement. We are talking 21 mpg here. That is brutal. I'm not even taking it above 4000 rpm, and that's spirited driving. I'm in Ontario. Its pancake flat here. Like I said, car runs great and I really quite enjoy driving it but something is amiss here.
I think something is broken besides the low tire pressure if you're getting 21 MPG on E10 gasoline (not E85 or anything w/ more than 10% alcohol). I have never received less than 28 MPG over a tankful or two in my Ti w/18" tires. The Michelin Pilot Sport 3 tires
use a low rolling resistance rubber and design despite being an "Ultra-High Performance Sport" tire, so the drag everyone talks about when using those tires is not likely there at that 1-2 MPG level if they're any worse at all over the other OEM tires.. That tire gets a 9 out of 10 on rolling resistance ratings at Michelin. I recently put narrower 215/50x17" Blizzak WS-70 snow tires on my car and the gas mileage got slightly worse. That could be simply due to colder temps. though.
Normal MPGs for me lately with a full throttle blast here and there (every day) and my winter tires on are 29-37 (using mid-grade gas). The MPGs really drop in constant stop and go traffic so if all your driving is that that's a part of the problem too. I have around 5000 miles on mine and it seems to run better all the time. Yours will most likely improve too (you've only got 3400 kilometers on it) as the engine wears in (breaks in) more.