Hi i was wonder what gears i should get for my 2002 supercrew. Im planning on putting a 4" lift with 305/50/R20 with 20" rims. I want to get a little more off the line with the lift and tires but i dont want my mpg to go down to much. And i will be driving highway. If you guys could please help me it would be great.

Also i was thinking about getting a programer for my truck to get some power and better mpg. What do you guys know about promgramers for a gas truck?
Thanks

 

4.10 at least.

 

Will that affect my highway driving?

 

If you gear it right, it will help your highway driving and fuel mileage out. It will help the truck compensate for the bigger tires. Let's take some ratios. Assuming that your original gear set was a 3.55 and you had the 255/70-16 tire, take those numbers and put them into a tire height to rear end gearing ratio. The 305 tire you want to use it 32 inches tall. The 255 is 30 inches tall. 30/3.55 is ratio one and 32/x is ratio two. Cross multiply and solve for x and you get a ratio of 3.78. The closest you will get to that is a 3.73 (do some research at Randy's Ring and Pinion, find out your axle and see what the ring gear option are.) With a 3.73 you should be pretty close the the truck not really knowing that is is turning bigger tires. Now if you have a 3.73 rear end, then your really shouldn't need to regear as your not going with that big of tires.

 

Zap, Are you running stock gears on your truck?

 

Okay. Im going to look it up. And would i need to change the front gears also?

 

Yes. Unless you regear the t-case high gearing to a slightly lower one. (some are 1:1 I'm high and some can be changed). May not apply to fords though.

I'm not sending this from my iPhone while driving.

 

What would be the best and cheapest way for the front gears?

 

Being a Supercrew you probably have 3.73 gearing. Your going to a 33" tire from a stock 31" tire.. no need to regear. Your looking at $1600 for front and rear. And yes you have to do the front if you have 4wd. If you have different gears and put it into 4wd, you will blow it up.

IMHO, I wouldn't regear... I'm stock 3.55 running 35" tires and honestly, I get the same gas mileage as I did with my stock tires... I might be getting 1mpg less, but at certain speeds on highway I get better. I say, don't waste the money on gears, your not running a big enough tire to really worry about stress.

I say get a programmer and see what you think after. Programmer will give you enough power increase to cover going to a bigger tire, not like your going so big you lose a ton of power anyways. Go look at Edge Evo, Edge CS.. Or go check out PHP, Powerhungryperformance and look at the Gryphon with custom tunes.

 

Okay. Would the programer help in mpg? And what all would i have to do to my motor to make it safe for the programer? Cuz on diesels dont you have to put a cold air intake and different exhaust and injectors to make it run right?