MPG ?'s

[littlered351]

I have a 2002 2.3 5 speed Ranger currently lifted 6'' on 35's. I have a pretty long commute now and am thinking of lowering my truck to get better mileage.

This will be lowered from stock not from where it is now.
Looking at 3'' coils for the front ( I already have camber bushings) and useing a 95 up explorer rear axle (already sprung under) with a 3.27 ratio. Wheels and tires will be factory explorer 17's with 225/45/17 tires. I'm hoping to get 30 mpg out of it instead of the 20 I get now.

Does anyone out there run anything close to a 3.27 on a 4cyl with 25'' tires? If so what kind of mileage do you get? Do you think I'd be better with a 3.55 ratio?

Any help or comments are appreciated.

 

[JoshT]

If my math is right and what you think you get MPG is correct (seems a little height to me but not my truck). You should be close to 30 mpg with just the tire change. That said I doubt that you would really want to keep that ratio with the size tires you are talking about, I really don't think you would be happy with the truck like that. I don't think you would be able to touch the gas without spinning the tires. The change in gear ratio will affect your MPG but I couldn't say how exactly. According to the gear change calculator in the tech library 3.27 would keep almost the exact same performance you have now. It also suggests 3.27 -/+ 0.30 for your high or low gear ratio. Going higher (numerically lower) would give you better MPG and higher top speed, but less acelleration and pulling power. Going lower (numerically) would give you better acceleration and more pulling power, but less MPG and lower top speed. But there's also the fact that the smaller tires will be less of a load on the motor so the performance and MPG will likely increase regardless of whether you go gear high or low for the tire size.

 

[littlered351]

I have went to a 5.13 gear now instead of the 4.56 I have listed in my sig.

My truck came stock with 3.73 and 225/70/15's and it got approx 27mpg. I was thinking that the higher gear and the shorter tire and less wind drag from lowering would get me the 3mpg better on my highway commute. I live in the North GA mountains and my fear is that high of a gear I'll have to downshift at every hill and loose what I'm trying to gain.

Do you think a 3.55 gear with a 25'' tire would be better suited?

 

[mp3deviant721]

Sorry about thread jacking but doesn't lowering in general raise gas mileage? Combine that with slightly taller but same width tire shouldn't that give you some raise in MPG? Cause I'm really considering lowering my truck to see if I can hit approx. 22-24mpg.

 

[JoshT]

Sorry about thread jacking but doesn't lowering in general raise gas mileage? Combine that with slightly taller but same width tire shouldn't that give you some raise in MPG? Cause I'm really considering lowering my truck to see if I can hit approx. 22-24mpg.

Lowering cause lower MPG, I doubt it. IMO what makes it seem that way is that when people lower a truck they usually also get smaller tires. As for going to taller tires and gaining MPG, that's because the odometer and speedometer are no longer correct and are showing lower than actual miles driven and slower than actual speed. It may not be hurting it much but the taller tire isn't helping MPG unless the gearing has also been changed to accommodate it.

 

[JoshT]

For a 25" tall tire I think you would be happier with the 3.27 than 3.55 gear. I think the 3.55 gear is going to accelerate fast but not give the MPG you want. The 3.27 will probably be about mid range gear, if not slightly more to the economy side.

 

[rat_ranger]

My 03 is lowered 4/5, is a standard and has some WIDE tries on the back, and on the highway will get me around 30mpg if I stay between 70-75mph. the rear tires are 225/30r20s, and I checked my speedo against GPS and a speeding ticket so its pretty darn close. I got 35mpg once, still not sure how everything went so perfect that day.

 

[littlered351]

Rat Ranger, Do you still have the stock 3.73 rear gear? Your rear tires should be about 25.3 tall. So very close to what I want to run.

 

[ES894x4]

keep your rear 3.73, if you had 4.10 i would say grab a higher ratio but you should be perfectly fine at 3.73, i wouldnt waste the time upgrading to just a 3.55, and 3.27 will be putting you on the tall side for a 4 banger, these motors operate with peak tq at 3750 and peak hp at 5k so spinning them up doesnt cause a drop in mpg since these truck weigh at a minimum 3100 and the motor has as much power and tq as a honda b18. i pull 27-28 all day in my stock duratec so 30 should be easy to hit