MPG question

[zonker]

unless u see the gas in the fill neck, u really don't know if u made a complete fillup, and that can give variances in mpg readings.

when i want to check for "best" mpg, i fill the tires to 36lbs, top the tank off until it is in the neck, shift at 3000rpm or below, and drive the same 70 mile loop at no more than 70mph.

my zx2, which usually does 30mpg or so in "real world" driving, will pull 38mpg on that loop under those conditions. i haven't taken the mustang out for a mpg try yet... maybe when the weather is better (damn rain).

 

[AngelaS]

Correct tire pressure and limiting your throttle to the smallest amount you can manage to take off from lights are the two easiest things you can do to raise mileage. Being really gentle on the throttle won't slow you down much in the city either, it just won't be much fun.

 

[65ShelbyClone]

unless u see the gas in the fill neck, u really don't know if u made a complete fillup, and that can give variances in mpg readings.

That is why economy should be averaged over multiple tanks of fuel. It also isn't a bad idea to fill up at the same pump for consistency. I find that my economy seldom varies more than ±0.5mpg even when using different stations.

 

[Delray Dude]

That is why economy should be averaged over multiple tanks of fuel. It also isn't a bad idea to fill up at the same pump for consistency. I find that my economy seldom varies more than ±0.5mpg even when using different stations.

Agreed. I have kept my mileage and fill ups for my Mustang since the day I bought it. and yes the mileage from fill up to fill up ranges in the ±0.5mpg for me - even if i use the same pump. I do know that you can reproduce exact conditions each tank - but I'm fairly close on mine.

But I have a few years data and i also log when i do something to the car (i.e.: adjust tire pressure, new timimg belt, new O2 sensor, etc.) and somethings you can see an immediate swing of over 1-2 MPG - especially once I was getting an avg of 25 for 3 tank fulls and i checked tire pressure and found them all to be in the 20 to 25 range. adjusted and the mileage jumped back up the the 26.5 range.

I am real curious to see what my mileage will be after the next fill up the the non-ethanol fuel - I'll post my results once i get some data. I'll fill the tank near the end of this week and usually takes a week to drive it off.

 

[junkyardwarrior]

Wow. All these 2.3's running in mid-upper 20's for MPG.

Might as well have a GT or LX with a 5.0.

Mine is a '93 LX with a T5, 8.8 with 3.55's (was originally a 7.5 with 3.45), speedometer is dead nuts at 65 (GPS). Also has 4 wheel discs and V8 front brakes. Slightly heavier than the original 4 cylinder stuff-oh and I also added 225/60-15 tires (the cheapies).

On a fresh tuneup in the spring/summer, it normally gets about 34-36 mpg. Winter time 30-32. Both figures are mixed driving. About 200 miles city/200 highway. And normally I run about 360-370 miles on a tank of fuel.

Have tried lots of different things to help MPG. Cold air kit doesn't help. Neither did the Ranger header. I actually put the factory silencer , air box, and everything as well as the cast manifold back on. ICM failed in the fall of 2010 and replacing it-oddly didn't help a thing as far as MPG. I never noticed any loss before it failed. I do, however, keep the plugs new (well...I change them every 25,000 miles) and keep 44 psi in the tires. Rides a little rough but it helps fuel economy immensely. Also I don't drive it with the right foot on the floor. Doesn't do a bit of good. Stupid little engine doesn't make any more power on the floor as it does at 1/2 throttle (torqueless turd). And RPM doesn't do anything but make it sound buzzy. So I usually shift at or around 2500-2800 RPM. Any more is a waste. O2 was new about 50,000 miles ago. Air filter...man come to think of it, the filter hasn't been changed since I bought it and I've put 75,000 on it. Better go have a looksee as soon as the weather lets me.

Other than oil changes and spark plugs, this thing has been "almost" bulletproof. It's got a good little rattle every once in a while when starting it cold but it doesn't seem to bother it once it's warm. Best I can calculate, it's got 247,000 miles on it now. The T5 is about on it's last leg though. Getting noisy.

 

[65ShelbyClone]

And normally I run about 360-370 miles on a tank of fuel.

Until it's empty or what? 360-370mi on a 15gal tank is 24-25mpg, not 34-36.

 

[Delray Dude]

Wow. All these 2.3's running in mid-upper 20's for MPG.

Might as well have a GT or LX with a 5.0.

Mine is a '93 LX with a T5, 8.8 with 3.55's (was originally a 7.5 with 3.45), speedometer is dead nuts at 65 (GPS). Also has 4 wheel discs and V8 front brakes. Slightly heavier than the original 4 cylinder stuff-oh and I also added 225/60-15 tires (the cheapies).

I run a similiar setup - '93 with an 8.8 (but have 2.71 gears) and a t-5. Have the Weld wheels - back ones are 255/60 - 15. (yes they fill the wheel well).

On a fresh tuneup in the spring/summer, it normally gets about 34-36 mpg. Winter time 30-32. Both figures are mixed driving. About 200 miles city/200 highway. And normally I run about 360-370 miles on a tank of fuel.

What fuel are you running?

I have average 26 and mostly highway. Atleast I have with this ethanol crap in the fuel - a few days from now I'll know what my MPG is with non-ethanol fuel - i can tell it is getting better on this tank since i found a local station that sells ethanol free.

Have tried lots of different things to help MPG. Cold air kit doesn't help. Neither did the Ranger header. I actually put the factory silencer , air box, and everything as well as the cast manifold back on.

I've had different results with the ranger header. added alot more power to the car. I could see it not helping much if you still have the cats on the car, but i'm cat free and the header made a world of a difference along with removing the silencer. even if the ranger header did nothing in the power department, you still will loose at least 20 pounds of dead weight.

I do, however, keep the plugs new (well...I change them every 25,000 miles) and keep 44 psi in the tires. Rides a little rough but it helps fuel economy immensely.

I keep the tire pressures in my car at 45 too.

Also I don't drive it with the right foot on the floor. Doesn't do a bit of good. Stupid little engine doesn't make any more power on the floor as it does at 1/2 throttle (torqueless turd). And RPM doesn't do anything but make it sound buzzy. So I usually shift at or around 2500-2800 RPM. Any more is a waste. O2 was new about 50,000 miles ago. Air filter...man come to think of it, the filter hasn't been changed since I bought it and I've put 75,000 on it. Better go have a looksee as soon as the weather lets me.

I've found that the best vacuum i get on the highway is in 4th gear at 2500 rpm - any more or less results in the vacuum to start dropping below 15 HG, with my gears this works out to running close to 70 mph in 4th. One of these days I'll find an 8.8 with 3.55 or 3.08 and slide it in and see where I cruise best.

 

[zonker]

i have this 90 mile freeway loop i drive when i want to check fuel economy... i start with filling the tank till gas is above the fuelpipe restrictor and i use the same pump every time. Then I drive no faster than 70 mph.

i've taken a couple 2.3's on that run... a stock '79 mustang w/C3 and my '92 mustang w. A4LD.

'79 - 23.75 mpg
'92 - 26.84 mpg

best i've seen so far is with a '98 zx2 2.0 zetec/5spd... 38.6 mpg

 

[FVBonura]

Update

Last three tankfuls were at 44 psi tire pressure and I made over 25 mpg on each.

If your tires are rated to 45 psi max put them to 44. I love the hard ride and outstanding road feel. The MPG is a plus too.

I just did another oil change, trans fluid change, cleaned out the throttle body, upper intake, and IAC valve. I also changed everything to full synthetic. I will report any improvement in about two weeks.

44 psi is king!!!

 

[bigblockbob]

Last three tankfuls were at 44 psi tire pressure and I made over 25 mpg on each.

If your tires are rated to 45 psi max put them to 44. I love the hard ride and outstanding road feel. The MPG is a plus too.

I just did another oil change, trans fluid change, cleaned out the throttle body, upper intake, and IAC valve. I also changed everything to full synthetic. I will report any improvement in about two weeks.

44 psi is king!!!

Any improvement? Two weeks have gone fast! I have a 92 Hatch/auto that is stock. I am currently getting 21 mpg 90% highway/10% streets. Recently the trans started revving to about 4200 in first and shifting hard into second. Once it warms up it seems to do better. I don't know why the trans is doing this? Changing out the 8 spark plugs got me a 1 mpg increase over previous calculations. I do get a CEL sometimes and I should pull codes to see what it is?

 

[Shawneebear93]

I get around 25mpg mixed driving, drops to 22 or so in the city. I drive like an old lady, not kidding.

 

[realtripp]

My 1990 Mustang did great on fuel mileage after I did the 2.3T/T5 swap.

I netted 30mpg on a long road trip with my brother. We went on a camping trip to an offroad park south of Indianapolis. Made it from home to destination on just 5/8 tank of fuel.

That was loaded down too. I am 230 lbs my brother is 275 lbs and we had several hundred pounds of gear in the hatch. The car was definitely squatting before we even got in.

I drove it like a grandma and only boosted on one on ramp. It surprised the hell out of me.