How much of a gas milage and power loss with bigger tires?

[red96camaro]

well, how much? I am gonna do the TT/shackle for hopefully 2 inches then wanna go with the PA 3" body lift. I hear 33s will fit but what are we talking for losses compared to my stocks?

 

[KEbert]

The power loss will be very noticable. The mileage is hard to tell since your speedometer will be incorrect. It depends on what gears you have now and what transmission you have,

 

[red96camaro]

how much noticable, would my intake make up for it? or more?, wow, that sucks

 

[Blaine122300]

If you have 4.10's, highway driving will be good. Probably better than stock for mileage, but it will be a little harder to get up to speed. If you want it for off, and on road, 4.56 gears would be optimal. Your intake will not do much for performance. A chip might help more.

Andy

 

[ChuckyD]

You might as well do the intake and exhaust also, IMO... any gain in power is obviously a good thing!

 

[SplashMan]

I hardly noticed any change in mine when I went to 33s. It was a little slower off the line(very little), but high end stayed the same and I actually get a little better gas milage now. Oh yea, I'm running 33x12.5s with 4.10 gears.

 

[red96camaro]

I am getting an exhaust as well.
All I know about gears is the higher you go the more easier it is to get top speed and the lower you go the easier it is to accelerate.
Am I correct on this?
What is in my explorer stock?
And how much do gears cost?
Most people with big tires run gears a well?
Sorry for all the questions but I am starting to look at 33's for after my lift but I sure don't wanna go there if the power loss will be more than my intake and exhaust would make up for and I like my gas milage

 

[Robert]

Looking at your pictures, you have the 255 70R16 tires. In 1997 the only axle that came with those tires is a 4.10 so that is what you have. My '97 came with the same tires and axle. When I put 265 75R16 tires (32" equivalents) I could barely feel a slight loss in power off the line. Once I get above 30 MPH or so, you can't tell. My mileage didn't change one bit with the taller tires. Maybe the increased highway mileage makes up for the loss getting up to speed. My daily commute involves about 10 miles of highway, 10 miles of stop and go 40-45 MPH and 10 miles of rush hour freeway each way. 18 months after installing my taller tires, I still average 18 MPG between fill-ups.

Fortunately, your '97 is easy to recalibrate the speedometer. You have a Vehicle Speed Sensor at the end of you transfer case. It is held on by one bolt. Remove it and count the teeth on the gear at the end. Go to Ford and get an identical one with 2 less teeth. If your is like my '97 was, you will have a 20 tooth black gear in there. You will need an 18 tooth yellow one if you go with 33" tires (19 tooth pink one for my 32" tires).

If you decide you do want to re-gear, 4.56 will put you back to your original over-all ratio and will perform the same as stock. Figure on about $800-$1000 to have your front and rear gears replaced. You probably won't find it necessary though.

 

[red96camaro]

robert-thank you so much, I guess my X will look like yours when I am done it seems. Why did you not go with 33"?

 

[Robert]

Because I put the tires on before I had any intentions of lifting it. When my current ones wear out in about another year, I will test fit 285 75R16s and see how they fit. If I don't have to do any cutting, I will probably go with the 285s.

 

[rustytr]

I still learn something new everyday here.

 

[KEbert]

When I went to 31's I really noticed the difference. But I also have 3.55's and a manual transmission. But I think if I had a KKM it would just about make up for the difference. That is about how much power I would say is lost.

 

[Sherwood]

I lost approximatly 3-4 mpg. I am running the 4" Trailmaster and 3" PA body lift with 33" Baja Claw's with 4.10 gears. Mine is an automatic. You have to figure in the bigger tires equals less power and the wind drag that the new lift and tires will slow you Ex down. Of course the Baja's are quite aggresive tires which mean they cause a lot of wind drag too. Just my two cents worth.

 

[Alec]

If you already have 4.10 gears, you should be fine. Like was said above, 4.56 would be ideal for offroading, but your 4.10s will provide a good mix of power and mileage. I run 3.73s with my 31s, so it's about the same.

Definately get your speedo recalibrated. Hopefully you have the mechanical type as was mentioned. If you have the digital type, you'll probably have to take it to Ford to get it calibrated.

 

[red96camaro]

thanks everyone, I will keep track of this post for when I get my truck lifted beyond the TT/shackles

 

[2001ExpSport]

I have 3.73's and 33's on mine. I noticed a difference the day I got the tires, but overall it drives the same and mileage is the same. With bigger tires you are actually getting better mileage than your odometer says, but it isn't a huge amount. I wouldn't worry about power loss. I have swapped around from stock to 33's just to see if it was a big deal and to be honest it drives about the same. Unless you have 3.08's you'll be ok. If you don't know look at the tag on one of the rear diff pan bolts. The first 3 numbers on the tag are your gears(3.08, 3.73, 4.10).