The reason why people see increase in MPG with power adders is based on engine efficiency. I'm pretty sure everyone can agree that an engine that can get air in and out of it with the least amount of restriction is going to be more efficient. I saw this firsthand on my 2003 Honda Civic Si that was rated at 26-31 mpg. With I/H/E and lightweight wheels I was able to get a maximum of 34 mpg and usually 28 around town. Of course, if you abuse the new found power, then that's another story.

 

Thicker sidewalls on the 16" tire because it has a shorter sidewalls?

 

I just put a T1R "Response" header and T1R b-pipe on my car. I did it to improve responsiveness in the midrange (I come from Subies and Jeeps, which are torque monsters, and still haven't gotten comfortable with the concept of revving the bejeezus out of my car to find its powerband) as well as to see what it would do for fuel economy. I'll report back here if I see anything worthy of reporting. Come to think of it, I'll just report back here no matter what.

 

I wouldn't expect anything less!

 

Just wanted to provide a quick data point here - I put in an Aspec CAI a little while ago, and tonight was able to get my best mpg so far in this car. Cruise control set at an average of 65 for the trip, I got 43.18 mpg on my 320 mile trip. A full 2 mpg better than I've ever been able to do before (my previous bests were making the same drive).

Other mods that might have affected fuel efficiency are my Eagle GT tires @ 40psi, and my Beatrush underpanel. Weather was mild, so I didn't need any a/c.

 

cut a hole in your floorboard and START RUNNING!

 

^^ youd be better than a hybrid

 

deleted my little front wiper (may be temporary)
then was able to pull the main wiper rotate it lower and reinstall more out of the airstream.
Other benefit is the view out the front window is awesome and uncluttered.
Granted, economy improvement is likely small but every little bit helps.

 

You should make a video showing the one wiper swiping the windshield. it will be interesting to see.

 

That looks way better, I think im gonna do that when I get home. I hate how cluttered that area looks.

 

Okay, here I am reporting back. I've run through just two tankfuls, so it's not super-conclusive, but I went from a consistent run of high 38's/low 39's to two tanks in 40mpg territory! Hurrah! I finally broke through, without having to sacrifice time or safety.

I'm going to credit the header/midpipe with a 1mpg improvement in my fuel economy. I also credit them with improving the driveability of the car in very pleasant ways.

Next up, and very soon, is lighter wheel/tire combo. By "very soon" I hope to mean "later today", hence my decision to post results about the header/midpipe now.

Very soon after that will be Yet Another Intake, this time a chambered intake with an external filter. I chose this design after a lot of research, all of which pointed to chambered intakes being the way to go on this motor. I have high hopes...

 

Very cool, not surprised by the gains

 

I just had my SSRI intake installed today. I usually get 37 with hard driving with a new oil change. 40-41mpg if I slowed down for a little bit and 46 with hypermiling. Now I would probably try the car with easy driving with a little bit of hypermiling to see what I get because I don't want to do too much hypermiling because the gas price is now reasonable compare to what it was. I will post the result in a week or two.

 

8 pages of reading and what i have learned is.............either use the "tow hook" method or "get out and push" method.

 

Super light wheels and narrow tires.
Best mods I did and got a measured 3 mpg increase.

 

lol.....disconnecting your brakes will give u the best mpg

hint - driving like u had no brakes i.e. technique is the fundamental factor

 

I think I've found a fairly substantial increase in mileage just by setting the right valve lash.

Service spec is 0.006-0.007" intake, 0.010-0.012" exhaust on the GD3 (if what I've read on this forum is correct). Before I was set at the lower number for each, which was good for top end power, but my mileage was stuck at about 31-33 consistently, unless I did some mild hypermiling in which case it would rise to 36-38. Must be how Honda EPA'd the car.

I recently reset the lash to the higher number of each spec and even on my monthly decarbon have-fun tank the mileage is up to about 36 (will calculate exact number tomorrow afternoon when I give the gas man the monies). It crossed half on the gauge at 176 miles and on the fun tank that doesn't ever happen above 140. I can't wait to try for mileage the next tank.

Two things I've noticed since the change: car has a LOT more low end torque to the point 2500 rpm shifting with light throttle doesn't feel like lugging and will actually keep up with traffic, and the pedal is super touchy! It won't go constant 25mph in 4th gear on level ground, as it will always be either in slow acceleration or DFCO. No in between. Never did that before...

 

The beat-the-crap-out-of-it tank got 34 mpg, still with my 3 mile commute to work and back. Included a lake road run too, meaning a good 5 minutes keeping it 4000+ rpm in the curves. <<<that one's to de-glaze the clutch, I do it every 3 months or so

Big trip tomorrow. We'll see how it does, but I do know it's less than 1/4" off full with 80 miles on the tank, without a top-off or any hypermiling. I am so THRILLED

 

The next tank was a thrasher, that one netted 36.3 mpg. Tank after that was a bit more conservative and got 39.4 mpg. UG said 39.3, close! Will see if it holds true.

Current tank will roll the donuts at 50 psi so we'll see how much of an effect that has. They have been at 40.

If the UG is any indicator it stays in the 40-45 mpg range at 60 mph. I had one worked on at the shop and they put 32 psi back into it, it took 5 mpg off at 60 mph. Big diff. (wasn't a puncture, was a rim issue)

So basically if you're having mileage issues:
tire pressure
oil
valve lash
alignment
brake binding - check those caliper slide boots every oil change
an engine load indicator is nice...

Gas gauge likes to fool me into thinking I'm driving a V8. Both the UG and gas station fill confirm that my needle points at E with 2.4 gallons left in the tank. Ugh. No wonder the light always turned on an hour after I thought I was out!

 

my escort gt had it just if it acted up then there were other issues my friends froze and got amix of half and half