3.73 to 4.11's is it worth it?

[SOLISIMO]

My truck is starting to feel sluggish and really have to romp the pedal for this thing to move. Came stock with 3.73 but w/ a calculator it states I sould be around a 4.10ish. Is the change noticeable or should I just bump up to the 4.30's.

 

[alaskanexpy]

if your going to do it, you might as well go 4:30s...after the cost you might as well get some enjoyment out of it!

 

[SOLISIMO]

if your going to do it, you might as well go 4:30s...after the cost you might as well get some enjoyment out of it!

But will my city mileage be affected?

 

[alaskanexpy]

city MPG should possibly go up because the truck has to work less to get going, highway MPG could possibly suffer due to higher RPMs when cruising . so it depends what kind of driving and how much you do.


i currently have 3:73s in my excursion, they came with optional 4:30s from the factory. the guys with them get better city mpg and marginally lower highway MPG. but the power off the line is much better. so its a trade off as to what you need verses want. that said i'm saving up for 4:30s

 

[SOLISIMO]

Ok great, we really dont do that much city. Its a heavy truck with all the shit on it so Im sure it will help

 

[alaskanexpy]

yeah plus with your larger tires it wont be a drastic jump. just slightly better then it was stock. problem is if you did the 4:10s you'd be wishing after awhile you just went ahead and did the 4:30s. plus with your 6 speed tranny you should really have little impact on highway rpms...slight but nothing crazy i would not think.

 

[SOLISIMO]

Schweet!

 

[Thermo]

Soli, what you need to look at is when you are on the highway, what is the RPM of the motor? The big thing you need to keep in mind is that if the motor gets over 2200 RPM when cruising, your mileage is going to start taking a nose dive. With your truck completely stock, you should have hit 2200 RPM at about 72 mpH. With the bigger tires, you are going to hit it now at about 80 MPH (actual speed). If you install 4.30 gears and get the speedo calibrated, you will hit the 2200 RPM line at about 65 MPH. So, how fast do you drive? Atleast with the 4.11 gears, you will still hit 72 mph without a significant hit to the mileage. But, the question is, are you willing to spend $1600-2000 on new gears and to have them installed for the slightly better acceleration? Not saying yes or no, but that is the cost.

 

[toms89]

are you willing to spend $1600-2000 on new gears

You should be able to get a gear set for between $150 to $250. So for front and rear you are looking at $500 maybe for parts. Labor should not be that high or you should look elsewhere.

When I changed my gears in my mustang the ford racing gearsets came with oil, shims, new pinion gear nut and friction modifier. If you wish to replace pinion seal or other items add a few bucks.

I think what alaskan expy stated is spot on. I also think changing your gearset is one of the best mods you can do as far as performance and feel. I don't think you will see much lost in highway mpg unless you are cruising at high speeds constantly as it will reduce the load on the motor.

 

[toms89]

Hmm. Just re-read your original post... Tough call between 4.11's and 4.30's. Whats the difference between your current and original tire size? 4.11's increase your rpms or reduce your mph by about 10% over 3.73's. 4.30's equal 15% over 3.73's. If your tire size increased by 5% or more I would say 4.30's