gas loss with gears

[Stang39r]

i dunno what the stock gears on a 95 gt would be but im curious would a 3.73 and a 4.10 gear lose on gas mileage?? im only gettin 15 as is and i dont wanna go any lower than 12. thanx

[1BAD89]

Your only getting 15? Tell me more about your combo....5- speed? I'm guessing an automatic with the kind of gas mileage your getting. I used to get 23mpg highway/city in my fox body 5 speed, with 3:55's. I need more info.

[2FastLX]

If you're only getting 15mpg you are either putting your foot down too much, you have enough mods for your car to be considered a drag car only, or you have tuning issues. My last Stang ran mid 13's and got 18mpg even with my lead foot. That was with 3.73 gears. Your car is a bit heavier so that will make some difference, but I can't see 15mpg on a daily driven Stang. More info is needed, but generally stepping up in gear size isn't going to make a ton of difference unless you do a lot of highway driving. And even then it won't be so much you should regret the gear swap. 75% of my driving was on the highway and I never really noticed any difference myself.

[302 LX Eric]

I switched from 2.73 to 3.55 with little to no real difference in MPG. Of course, I don't drive my Mustang enough to really make a difference for me. It's just a fun car for the weekends, nice days, and the track.

E

[Stang39r]

sorry for takin so long but....i have a completely stock 95 gt vert. i had the car tuned no longer than 7 months ago. no mods on it at all. like i said, bare stock. i have never really gotten anything more than 15 and i ALWAYS drive it hard. im still just a teenager so i like to punch it off the start. ive gotten it down to 13 mpg sometimes but hw mpg is about 18-19. never gotten more than that. anything i should look for to see better gas mileage and also about my main question...

how many mpg am i lookin to lose if i go to 3.73 or 4.10?? thanx for any info given

[Stang39r]

bump....er

[Rosco]

Same here. I'm not really sure what the Size of my tank is, cuz i've never filled it up from empty, as my gas gauge drops off with 1/4 tank left. I've got a stock '91 5spd. and I'm getting about 240mph combined highway and street use. Although I'm not driving it hard either on highway or street. It's still not the kinda weather here in NY that I wanna be running hard. Running on the highway at about...1800-2000 rpms, and about 1900rpms in 4th gear for street..if not a little less. Oh and I have 2.73's in it. Any ideas on how i Could Improve this?

[302 LX Eric]

Stang39r - It depends. It depends on how you are going to drive your Mustang. Are you going to continue to keep your foot in the throttle all the time - like you are now, hence the crappy gas mileage. Or, are you going to ease up a bit? If you could tone down your driving style, you could probably throw in some 3.73's and hardly notice a difference in MPG. However, if you keep the lead foot, MPG will decrease, maybe by as much a 2 MPG.

It all really depends on you.

E

[302 LX Eric]

I'm getting about 240mph

Hey man, that's not very safe. Slow down a little.

E

[PKRWUD]

Rosco-
You don't need to know the size of your tank. To figure your mileage, fill the tank as high as you can, and write down the mileage. Drive it until you get to the point where you normally fill it up. Fill it up, and write down how many gallons it takes. Do this for 3 fill-ups, writing down the amount of gallons it takes to fill it each time. After the third time, add together the gallon totals from the three fill-ups. Check your mileage. Subtract the mileage you wrote down before the first fill-up from the mileage after the third fill-up. Divide that number by the gallon total. That is your average gas mileage. You can do it on fewer fill-ups, but it won't be as accurate. Posting this number will give everyone a better idea of where you're at.

Stang39r-
Expect to see a drop of between 2 and 3mpg with the gear change.

Take care,
-Chris

[NO SLO PK]

FWIW, I was told that more aggressive gears provide better city mpg, all else being equal. The steeper gears are supposed to promote higher vacuum levels during city driving, which equates to better mpg.

One of these days, I will put in those 3.55s I've had sitting in my garage for the past 7 years .

[Mr 5 0]

NO SLO PK:

Steeper differential gears will allow you to upshift (to a higher transmission gear) sooner - especially in traffic - which saves gas, as the lower the (transmisssion) gear you're in, the higher the engine RPM, which in turn uses more gasoline.

The 5.0 engine is interesting when it comes to gas mileage. I find that if I watch my driving and use cruise control I can get mid-20's on the highway, easily (I saw 28 mpg on one 500 mile trip) By the same token, if i get in it just a bit, WHAM! I'm looking at low-teens or worse for mileage...and I'm near-stock.

I drive somewhat aggressively but not to the point of really 'beating' my Mustang and I consistantly see an average of about 18 mpg with a well-tuned, near stock, 5-speed 5.0 running 3.55 gears. Go figure.

FYI: Cold temperatures have a negative effect on gas mileage. You can lose a few mpg in really cold weather, plus if you idle a lot to 'warm it up', you're getting zero mpg, then. It all factors in.

[NO SLO PK]

5.0:

I suppose there's that angle too. But in city driving, the steeper geers will permit the car to accelerate using less throttle. Less throttle equates to a higher vacuum condition, which directly relates to reduced fuel consumption. Many fuel economy gauges use engine vacuum as input. The higher the vacuum the better the mpg.

[MidNiteBlu 5.0]

I always get like 14.5 - 15 mpg. However this is ALL in town no highway at all as it is my daily driver to school and work both of which are not very far from home. I dont drive it very hard but i wouldnt say that i baby it I still need to check my timing though maybe that could be a problem.

Later