gears & gas mileage..............

  • Sponsors (?)


jrc_03_gt said:




:uzi: :bs: i'm not lying :mad:


in all seriousness. both times i've put in 4.10's my milage went up. there is no way to prove it exactly, but i'll try to explain it. ford has a optimum performance range in the rpm band. well they gear the car so that when you hit 5th & cruise it's below that optimum range, baisically so their emissions are better. now when you go from 3.27's to 4.10's the engine isn't working as hard to keep the rev's up when you're cruising, cause it's better in it's power band. therefore making the engine actually more fuel efficent, but efficient emissions are sacrificed :nice:
 
I dont really know much, but I agree with c2see21. Especially in the city I could see it getting better mileage unless your having too much fun with it. My brother's GT, which is gone now, had 4.10's and still got a little less than 300 from a tank. But he had a T/A and used 93 octane....I dont know if that'll make a difference. Anyways, all of his driving was in the city. I guess it's cause the gears make it alot easier for the car to take off, and he also used 5th everytime religiously. Seriously though, I think one of the major reasons that people's mileage goes way down after gears is cause it's too easy to floor it and have a little fun......dont blame ya.
 
Fact: The GT's computer was designed to run a certain way, that way is w/regular gas, not mid, not premium. I guarantee that if you continue to use premium for a long time w/the stock computer, you will end up having some issues. It's gonna happen.

That being said...you guys that fill up every once and a while w/a higher grade aren't hurting anything, YET, you aren't helping either.
 
c2see21 said:
:uzi: :bs: i'm not lying :mad:


in all seriousness. both times i've put in 4.10's my milage went up. there is no way to prove it exactly, but i'll try to explain it. ford has a optimum performance range in the rpm band. well they gear the car so that when you hit 5th & cruise it's below that optimum range, baisically so their emissions are better. now when you go from 3.27's to 4.10's the engine isn't working as hard to keep the rev's up when you're cruising, cause it's better in it's power band. therefore making the engine actually more fuel efficent, but efficient emissions are sacrificed :nice:

Did you ever adjust your speedo after installing the 4.10's. 4.10's should have the effect of having smaller tires. you wouldn't get better milage speed for speed. If you didn't adjust the Speedo than your putting exta miles on your car that your not driving in addition to not knowing how fast you are really going. by the way the optimum range thing sounds like total bs :bs: when your traveling at 30mph(60mph, 100mph.. what ever) and your rpm's are higher than when you had stock ratio, you are burning more fuel. Emissions is seperate from milage, it just means your burning cleaner.
 
XtorT'r said:
Did you ever adjust your speedo after installing the 4.10's. 4.10's should have the effect of having smaller tires. you wouldn't get better milage speed for speed. If you didn't adjust the Speedo than your putting exta miles on your car that your not driving in addition to not knowing how fast you are really going. by the way the optimum range thing sounds like total bs :bs: when your traveling at 30mph(60mph, 100mph.. what ever) and your rpm's are higher than when you had stock ratio, you are burning more fuel. Emissions is seperate from milage, it just means your burning cleaner.


yes my speedo is corrected per a brothers speed cal. & as for the optimum power range, tell that to the ford engineer that told me about it. if you don't believe me fine :rolleyes:

& since you dont' believe me, here's a little test for you. go get in your stang & go to a highway & cruise at say 50mph in 5th, then try to go faster. it will pull against itself, because it's out of it's power band. no put it in 4th & do the same thing, you will accelerate just the way you want to & everything will be normal, as compared to when it almost bogs when you do it in 5th. this means the engine is working harder to get up to speed which inturn makes it less fuel efficent.