I was not going to dispute what you said as you obviously are trained and qualified in your selected trade but your last statement shows you may want to do a bit more research into direct injection.

A quick google search finds that gasoline powered DI engines do in fact suffer from soot issues.

 

at ~ 17xx miles, 22.9.

 

We just pasted our first 1000 miles.

So at 1000 miles we are avg 26mph and we are avg 22.6 mpg. We sort of was not watching thes numbers the first couple of days we had it. It is so much fun to punch it. Starting next week my wife will be driving on the tollway to work so the next 1000 mile numbers will be much different.

1000 miles
26 mph avg
22.6 mpg avg

 

With mine, don't have an SS, just a 2LT and I'm averaging about 17.7 mpg according to the DIC. It's acutally went down from 18.5. I'm babying it right now till I get to 3k. Thought maybe it was the 20"s I put but the over all height is not much of a difference from stock. The 1st few weeks I had stocks the mpg wasn't great either. Been running regular. Maybe should I try mid grade?

 

yeah 20s would kill your gas milage

 

Going great so far, just put in my first tank of 93 octane.

 

How heavy are those 20's over the stockers. An as i tell everyone else, if you getting under 22 for an average, it's your driving ,not the car. Please don't take that the wrong way. We all choose how to drive our own cars, but unless you drive 2mile (as in 10560 feet) or less trips all day, sit in traffic alot, drive at altitude pulling a load, frequent fastfood windows, or idle in the airconditioning for hours.....you should never see mileage that low. Unless you want to that is. Your car (unless you do what i wrote above and is not broke) should get 22mpg min in the city, 28 min on the highway. 87 octane or 94 octane will not MATTER.
If you care about mileage I can give you 10-20 things to do, and you will see 25+ in the city and 32+ on the highway.

 

Huh? So they _may_ be a little heavier than stock (maybe not... depends on the wheel choice), but "20's killing gas mileage" is a pretty broad statement to make. Assuming they're 200# heavier in total, if I carry a 200# passenger instead, are you saying that will kill my mileage too? Or is there something about a 20" wheel that suddenly changes the ability of the car to efficiently burn fuel?

I think the answer to both questions is NO.

 

I been runnin the speed limit lately, staying around 65, came all the way from Lake Havasu, AZ to San DIego with 31 MPG, and about 24-25 MPG in the local driving

 

The traffic I sit I would consider normal, I don't eat in my car so that cancels drive thru's, I use remote start and let the car cool down 4 about 5 minutes (I wouldn't think that would hurt it) and I don't haul in it. Between 55 and 65 mph (according 2 my gps navi) my speedometer is only off between 2 and 3 mph. I'm not gunnin her at all. And like I said before, the mpg was about the same w/stocks. I have no clue really... I called service and they said it takes between 4 & 5K miles for it to break in...

I'm gonna get the exact measurements of tire height and weight comparisons and go from there... I think I'll post a thread in a forum for feedback on other people who have 20"s once I get all the measurements together...