I know the comptech supercharger kit (or similar kits) are all over this board, but I cant find any info about actuall gas milage with the kit and without. I'm purchasing an s2k soon (older 9k motor) and I'm already concerned about the fairly meager gas milage... And while I have the urge to go quick, the thought of getting worse mpg then a suburban scares me.

 

If you are not in boost, the engine has the extra small load of having to drive the blower. This will not contribute to any drastic decrease in fuel economy. My city mileage was about 25 mpg (Canadian gallon) before the blower and it's been about 24 mph since and part of that is due to me giving it boost because it's there. Highway mileage has suffered about 4 mpg but most of this can be attributed to my 4.44 rear gears. They increase my cruising rpm by about 8.3% but my mileage decreased by about 10%, so the equivalent of about less than 1 mpg due to the blower. Of course, on a long highway cruise, I'm not into the boost to speak of.
If you are constantly into the boost, then you will suffer horrible fuel economy, but that is part of the thrill of having that extra 100 hp. If you are worried about fuel economy, you shouldn't be considering adding that much hp to the car. No pain, no gain. There's no free ride.

 

It stays close to stock if you keep your foot out of it.
Expect close to 20mpg in town, maybe less depending on the stop and go traffic. It gets worse with the application of the throttle.

A N/A car can get as bad as 8mpg on the track, at WOT all the time.


Moving to FI

 

Mine has dropped since the SC went in, but I can't give you any hard number syet. That will follow shortly hopefully.

 

i average around 21 - 24 depending on how much i have to drive in the city.

 

If you keep it out of boost you will keep close to stock gas mileage, floor it all the time and it will get pretty low, but even a NA s2k gets pretty bad gas mileage if you VTEC all over the place.

 

Comeon guys, I know there are some gas mileage 's out there that can give us some cold hard before and after numbers! Very interested in this topic...

 

Never had a stock kit, but would get about 18-19 mpg with a 7lbs pulley. Then again, I also had 4.57's. Cruising speed where I live is 80 mph, so I was in VTEC during my commute. That was at about 310hp.

My last 3 tanks with this current setup have been low 17's... 395hp. Still better than the Suburban you referenced. And quite a bit better lookin'.

 

Every car is going to be different man, and every driver is different. I average 22mpg consistently. Sometimes 23 if with a bit more sedate driving.

Still better than the 18mpg I got on my STI.

 

After my first fill up with the SC, I am getting 22. I also have the 4.77's so that will make a difference as well.