Newbie gearing question

[sjarvis]

I have a 98 XLT SOHC with a 3.73 rear end. What is the practical difference between this and other ratios? Which one is likely to get the best milage, better acceleration, ect.

I appreciate your wisdom and expertise.

Thanks- Scott

 

[TPLYNCH]

the lower the number, the better the MPG, but slower acceleration. Higher number, better acceleration, lower MPG.

 

[tenikiwon]

Can you add to that?

If you have a 3:73 vs a 4:10 you have more torque? right? but less gas milage? so which numbers higher, etc. What about tire size with this?

 

[Alec]

Try looking here:

Dead Link Removed

 

[Rx4phun]

i wouldnt say lower the number the better the mileage until you have tired 33s with 3.73, basically equating to 3.2 something

 

[Robert]

Bringing a thread back from the past

I'm just getting caught up on all the thread's I've missed over the last month ...... anyways,

Just because you have a numerically lower ratio, does not mean that you will get better mileage at the cost of slower acceleration. The goal is to keep your engine in it's optimum power band. If you go too low, you will not only hurt your performance, but also your mileage. Case in point, my '97 4x4 SOHC Sport averaged about 16.5-17 MPG with my stock 4.10 axle and stock 30" tires. When I swapped my stock tires to 32" tires, my mileage picked up to around 18-18.5 MPG. A few weeks ago I went up to 33" tires. My mileage has now gone down to 16-16.5 MPG. I am now below the optimum RPM range for my SOHC and am paying the price for it in performance and mileage. I will be upgrading to 4.56 to get me back as close to my original stock ratio as possible. Had I went the opposite and changed gears rather than tire sizes here is what the equivalent would have been:

30" tires & 4.10 = 30" tires & 4.10 (stock)
31.7" tires & 4.10 = 30" tires & 3.87 (first tire change)
32.9" tires & 4.10 = 30" tires & 3.74 (second tire change)
32.9" tires & 4.56 = 30" tires & 4.16 (where I'm going)