New Personal MPG Record

[bowtieguy]

filled up today to a new personal mpg record(barely). 337.4 miles on 12.704 gal to the tune of 26.55(old record was 26.53). the 30mpg goal eludes me still!

this 1995 olds 88(AT) has gotten this far w/ acetone,gliding, and weight reduction. driving is aprx 35%city/65% hwy. yes acetone HAS worked for me(more on that later on another thread). a few of you have stated getting 30+ with the same 3.8 GM motor, but my question is has anyone achieved this in similar conditions? short answer: NO!

let me explain. i know of 3 other owners of the same EXACT vehicle (all 1995 or 96), driving the same roads,weather,etc. they ALL agree that ANY city driving adversely affects FE. my hwy driving is 70 mph and a/c on also. since i joined gassavers a year after getting the car, there are no gaslog entries showing before and after acetone(sorry). i did document(every fill-up) that my avg WAS 20-22. after each mod is confirmed(or not) i will go back to leaving out the acetone. EVERY time this is done, FE drops back to org #s.

next up, overinflated tires. then a grill block. very confident in achieving 30mpg. soon the a/c usage will go down(possibly deleted) due to cooler weather. also using scan gauge on my wife's car(mine is not compatible) to help with "the nut behind the wheel." we have the same motor, so hopefully this will help.

one last thing. i'd like to extend a personal thank you to all of you who have posted your ideas and info. even tho i started hypermiling before joining this site, i NEVER thought it possible to go from a low of 20mpg to closing in on 30 with subtle mods.

[2TonJellyBean]

Good stuff!

Any chance you could try a tank at 55 mph and 55 psi?

[bowtieguy]

Good stuff!

Any chance you could try a tank at 55 mph and 55 psi?

sorry, i'd get "run over" on the FL turnpike(70mph). but i will try 65mph and 60psi(already increased). do you think 60 is too much?

[2TonJellyBean]

what are the sidewalls rated for?

i noticed a difference between 44 and 55... didn't think i would but i did

that and i couldn't really go beyond 50 psi with my bicycle floor pump and had to drop 50 cents! Grrr! L

[bowtieguy]

what are the sidewalls rated for?

i noticed a difference between 44 and 55... didn't think i would but i did

that and i couldn't really go beyond 50 psi with my bicycle floor pump and had to drop 50 cents! Grrr! L

sidewalls rated at 44.

something that might interest your 55mph suggestion: i drive a couple of stretches of 55mph zones out side the turnpike. so, to offset the 65mph(rather than 70) turnpike a bit, was considering driving those sections at 50. according to the scan gauge, that is the max FE for my wife's car, again, same engine.

[cfg83]

bowtieguy -

sidewalls rated at 44.

something that might interest your 55mph suggestion: i drive a couple of stretches of 55mph zones out side the turnpike. so, to offset the 65mph(rather than 70) turnpike a bit, was considering driving those sections at 50. according to the scan gauge, that is the max FE for my wife's car, again, same engine.

Ok, good stuff. That was going to be my next question. Are the transmissons the same for each car?

CarloSW2

[bowtieguy]

Carlos,

great question. no, her car(a camaro) is rear wheel drive. so, the trannies are not the same. however, i have noticed both cars have TC lock up near 50 mph @ 1500 rpm. 40mph is 2k rpm as is 65 and over(70 is about 2200). so, 50-65 is where i want to be right?

BTW everyone, ABA(more like AB...AB, since acetone can't be removed in tank) testing w/ acetone using the scan gauge on my wife's car leads me to believe it does NOT work(inconclusive) for the camaro. tried this tank to tank and came up w/ the same conclusion. can't say why, just want to give info on experiments w/out bias. the olds likes it, the camaro doesn't!

[cfg83]

bowtieguy -

Carlos,

great question. no, her car(a camaro) is rear wheel drive. so, the trannies are not the same. however, i have noticed both cars have TC lock up near 50 mph @ 1500 rpm. 40mph is 2k rpm as is 65 and over(70 is about 2200). so, 50-65 is where i want to be right?

Others can comment better than me, but if they're behaving the same, then I think you should be fine.

CarloSW2

[brucepick]

Granted this would be expensive to test, but how about synthetic transmission fluid? Mobil 1. I'm changing over but have no comparison numbers, sorry.

For my car, at every 4K mi. oil change I drain the tranny pan once and replace the old with Mobil 1. I calculated that's approx the same rate you change it at when you go 30K mi and then flush the whole system. My next such swap will be #3; with that done it will be approx 70% synthetic.

[bowtieguy]

Granted this would be expensive to test, but how about synthetic transmission fluid? Mobil 1. I'm changing over but have no comparison numbers, sorry.

For my car, at every 4K mi. oil change I drain the tranny pan once and replace the old with Mobil 1. I calculated that's approx the same rate you change it at when you go 30K mi and then flush the whole system. My next such swap will be #3; with that done it will be approx 70% synthetic.

i'm def with ya on the syn lubes. same with before and after #s 'cause i will NOT put dino oils in my cars.

[garyhgaryh]

Bowtieguy,
That's excellent mileage! I would love to get 30mpg on my Typhoon. What have you done to your 3.8 to get that type of mileage?
Thanks,
Gary

[8307c4]

I would highly recommend you read up on what under or over inflating does to your tires, your car, and the handling!

First you're reducing grip, your tire will have considerably less surface on the road!
Second your tire will wear unevenly, if you over inflate even 10% past the max psi printed on the side of the tire, the center of your treads will wear faster than the inside and outside, you will see.

Then your tire is bigger in diameter which affects your speedometer adversely, it could say you're doing 40mph when in reality you're doing 45!

All of these affect safety!
You may not be able to stop in time in a bad situation!

Perhaps you have cheap tires but if they're rated 44psi I doubt it, they are made of petrol too and my nicer tires cost $100 each so there's no way I'm sacrificing neither tire nor safety for mpg.

If you want less road grip why not try a slightly less wide tire in the first place, say you're running 205's you could try 195's, that would be a far safer option IMO. Don't forget to go up on your sidewall one number, so if they're 55's you want to go 65, this will help offset the speedometer misscalibration.

And yes, you can go one size up or down without the need for new rims, if you compensate via the sidewall height method then your speedo should only be off 2-3 mph at most legal speeds.