Car mods specifically for MPG?

[minigts]

Well I'd love to know how you can be at 10-15" of vacuum at that speed. At 70 on a straight flat road with no changes to the topography and maybe also downhill I can do 10-15", but I would say mine runs at 5-10" cruising at 70. When there are hills, turns or anything faster, I have to give it more throttle which all but cuts it to 0-5" vacuum maybe a little more. What gear ratio are you running and do you know roughly the RPM you're at?

[3nglenn]

Try some Acetone-I use 5oz per 10 gallons. I pull 35 MPG. 89 spirit T2 5 speed.

[Reaper1]

On the trip to and from SDAC18 from Jacksonville, Fl I got around 33mpg in my Shelby Z. Now, I had the car detuned with a simple orfice for boost control that limited boost to 9#'s and I was running 87 octane. To achieve this number the car had to stay at or below 75mph. Any faster and the milage would drop significantly. We had all my crap and all my firend's crap in the car, tools, ect. along with myself and my friend, so the car was loaded pretty well.

I also tried to keep the engine in vacuum as much as possible and while cruising I'm around 5-10".

Mods to the car:
FWD S5
+40's
AFPR (was set at 32#'s static at that time)
3" exhaust WITH cat
stock intake set-up w/ drop in K&N
FMIC
timing is stock 12*
engine, turbo, manifolds, cam, head are all stock
tranny is A555/A520 hybrid with 3.50FD
tires were stock sized 225/50/15
the car is lowered about 1"

I know I can get more out of it, but I have yet to hook the WB up to the computer's input to make it run a tad leaner in cruise. In thje city I get around 27-29mpg depending on hgow I drive. I usually try to not go in to boost much if at all, and I shift around 2000-2500rpm while maintaining as much vacuum as I can. I pay attention to my boost/vac as well as my WB to adjust my driving style. I've found that if you coast in gear, that only works for a little while, then the computer puts fuel back to the engine. I can help though. I've also found that rev-matching to downshift actually hurts fuel economy in my car.

On the highway, if you can stay near other cars you can increase your fuel economy by up to around 3mpg if you follow at the propper distance. I experimented with that using my boost gage, my WB and my 12-button traveler. In ALL instances of having another vehicle in the poximity of my car(even behind it) I gained fuel economy! The best, of course, was following a semi at a safe distance. Right around the 2-3 second interval worked the best(gee imagine that!).

[WLKivett]

Driving my Rampage (2.5, TII turbo, 3" exhaust and super 60 intercooler, 520 trans with 3.5FD) back and forth to work from the suburbs to downtown Charlotte. 10 miles each way with 20 stop lights no highway. I was averaging about 27 MPG then gas price went up and I started using 5th allot more, any time I'm above 40. My best tank has risen to 30.5 MPG. I alway drive like a paranoid grandma when commuting and wait to use boost on weekends.:-)

Just getting into 5th more often netted me a 13% improvement in fuel mileage.

Best Regards,
Landon

[minigts]

Would lowering your fuel pressure on long trips help at all? Just wondering because I have an AFPR and could do this on the road trips I take.

[Reaper1]

It *might* as it could reduce the amount of fuel being forced through the injector. However, the computer *should* be trying to compensate for the A/F by changing the pulsewidth of the injectors. I'd say that as long as you don't go high in your boost that it couldn't hurt to try it! Be aware that lower fuel presures makes the car more suseptable to vapor locking. That's an issue I'm currently fighting with my car, but I'm hoping to have resolved soon with a tweaked cal.

[JuXsA]

Well I'd love to know how you can be at 10-15" of vacuum at that speed. At 70 on a straight flat road with no changes to the topography and maybe also downhill I can do 10-15", but I would say mine runs at 5-10" cruising at 70. When there are hills, turns or anything faster, I have to give it more throttle which all but cuts it to 0-5" vacuum maybe a little more. What gear ratio are you running and do you know roughly the RPM you're at?

honestly I don't remember. It was 4 years ago this month. It was an area were it really was flat land. I think I may have been in Idaho or in Wyoming. I was some where around 3500-3800 rpms I think. It was in stock tranny so I think its a 3.5x gear. I drove 400 miles and I still had a little over 1/8th of tank. When I filled up I put either 10 or 11 gallons of gas though and that was with me topping it off. I couldn't believe it and I have never gotten mileage like that again.

Only thing I can figure was that with the conditions as they were and spinning the motor that high I may have been in the peak torque area of the engine.

The setup:
88 CSX-T 2.2 T1
2.5in exhaust
Garret turbo
FWD stg3 cal
grainger set to 8 psi

[turbovanman²]

Well I'd love to know how you can be at 10-15" of vacuum at that speed. At 70 on a straight flat road with no changes to the topography and maybe also downhill I can do 10-15", but I would say mine runs at 5-10" cruising at 70. When there are hills, turns or anything faster, I have to give it more throttle which all but cuts it to 0-5" vacuum maybe a little more. What gear ratio are you running and do you know roughly the RPM you're at?

Ha, the only time I get vacuum is at idle, down a hill or drafting, lol!

[Ondonti]

cruise control always helps my mileage.

[turzbo]

my freshly rebuilt 2.2 tbi just got 38mpg on a short highway trip, basickly stock, .30 over ported Tb with some factory spacers,intake/exhaust manny/ and a kinda cold air setup. 5speed no cruse at 110kmph

[turbovanman²]

my freshly rebuilt 2.2 tbi just got 38mpg on a short highway trip, basickly stock, .30 over ported Tb with some factory spacers,intake/exhaust manny/ and a kinda cold air setup. 5speed no cruse at 110kmph

Sorry, I call bull, TBI cars suck for fuel economy.

[Sloride]

on the way back from montreal i got about 5L/100 kms 850km to the tank. this was @ 100 to 110kms with 3" exaust+ mitsu turbo+ 17-15" vac (with the mitsu i had full tq @ 1800 so it was kinda like idling your way home)

2.5 L
523 3.50

We had to stop to piss twice before needing gas...

a warmer t stat will also help with mileage

[ssheen]

Sorry, I call bull, TBI cars suck for fuel economy.

Not necessarly true. The Bobs on Allpar Daytona/Laser can get in that range. Bob L has tracked his mileage going back years and years.

[contraption22]

Sorry, I call bull, TBI cars suck for fuel economy.

It depends simon... I got 30plus MPG out of a 2.2 TBI/Auto Horizon. Ig it were 5 speed, i could probably understand 35mpg plus. The problem you run into is with AAbodies and Minis that are really over-working a 100hp motor....

[turbovanman²]

Not necessarly true. The Bobs on Allpar Daytona/Laser can get in that range. Bob L has tracked his mileage going back years and years.

It depends simon... I got 30plus MPG out of a 2.2 TBI/Auto Horizon. Ig it were 5 speed, i could probably understand 35mpg plus. The problem you run into is with AAbodies and Minis that are really over-working a 100hp motor....

Wow, I've never seen those numbers in any TBI cars around here. I have a few customers who keep track and they average around 25 mpg,

[contraption22]

Wow, I've never seen those numbers in any TBI cars around here. I have a few customers who keep track and they average around 25 mpg,

I do not know Canadian geography. Do you live in a fairly mountainous region?

[turbovanman²]

I do not know Canadian geography. Do you live in a fairly mountainous region?

Yep, lots of hills, go East to Alberta and its flat from there to Ontario,

[turzbo]

Regina to Estavan and flat all the way. 2h drive

[135sohc]

can pull up to 34 mpg with my 2.2 tbi open highway trips

averages 29 locally

[turzbo]

It's no bull, on that trip, car went 256 km or 160 miles to 19 litres of fuel or 4.2 gallons, divided 160/4.2 and I get 38 mpg. No real tail wind nor head wind, kept it between 106 and 114 kph as my cruise isn't hooked up yet, also engine revs were steady at about 2450 which is way down from the 3000 it used to rev at with the old automatic tranny. In town driving it will get between 24 and 29 if i drive like a human being!