2002 screw fx4...lifted 6" and added 35" tires diff is stock @ 3.55

Some people say...."Dude. You HAVE to gear up or you will blow your Trans." One guy even told me "35's are the equivalent of driving with a 3,500lb trailer behind your truck every time."

Others have told me...."No way man, 35's aren’t a big enough leap to make a difference with a 3.55...I wouldn't do a thing unless you go to 38's or 44's"

The ones that say DO IT say go 4.88

The ones that say NO WAY say 4.88 would give me about 4mpg and a top HWAY speed of about 70

Both groups of people are what I would consider "in the know" reliable resources.....

So which is it?!?!?!?! Gear up or not...and if so to what? 4.10? 4.88? etc etc


P.S- I am using Edge Ev to get speedo tweaked and am around 1500 rpm at 60 MPH cruising speed. I noticed about a 12 mph diff when I went from stock to 35's and some loss of power but it does not feel like a 3,500 lb trailer behind me.

 

I had a 97 with 7" of lift and 35's. I switched out to 4.56 gears. I have no complaits. I got about 10MPG and at 70 mph I ran about 2250 rpm. No lifted truck is gonna be a road runner and certainly not great mpg. With stock 3.55's you're gonna feel really underpowered, especially when you get in some mud.

 

holy crap goin from 3.55 to 4.88 is a big jump i really dont think you need that big of a gear i run 35s on my 90 f-150 and i have stock gears not too sure what they are but they do fine i will be goin to 4.10 gears tho just for the added ooompphhhff ya know i would say low to mid 4 range would be good for you if you want more out of it

 

4.88s are too much gear for 35s. 4.10s would put you back around where you were stock and 4.56s would give you a nice performance increase but worse fuel mileage on the highway. You just have to decide what you want.

 

A straight answer is kinda hard to give.

Answer these questions and ll tell you what you should do.

1. Do you tow?
2. Do you Offroad?
3. How often are you on the highway?
4. What motor do you have.
5. Do you ever plan on going with a larger tire?
6. Are you happy with the performance of the truck? or is it slouchy.

Ill tell you now 4.10 gears arent worth doing too expensive for minimal gains

If you plan on Adding more lift and bigger tires go with 4.88's its not that low of a gear you would be fine untill upgrading to 37's or 38's

If you tow often then 4.56 or 4.88's are absolutely in need.

If you offroad then you will need to upgrade either 4.56 or 4.88's but 4.56's will suit you.

 

i have a 01 5.4 lifted 9" with 35's and 3.55 gears. ive been running the 35's for 2 years with no problems. i have a superchips tuner and my truck isnt that slow. i pull 2K RPMS at 80 and can cruise pretty good on flat ground.

you dont really need to change gears unless you tow, want your power back or you are going to upgrade to 37's or bigger. which is what im going to do and im going to go with 4.88s i think.

 

I have a 99 with the 4.2L V6 and 36's

My truck does fine with them, and they weight 125# a piece.

Would i rather have a gear job of course, is it a necesity no.

Go Gators...

 

1) I have a 1950 Crestliner Sportfish that weighs somewhere around 2500-2800 lb that I tow maybe 15 times a year with the farthest distance being 230 or so miles.

2) I offroad once in a while.I would say light to moderate off roading when I do go.

3) Mostly a daily driver around town..I would have to say i'm on the Hway as much as an avg person.

4) 5.4

5) no...but if I do, a gear up will part of the equation when I'm shopping around.

6) Can I smoke the tires on dry pavement? No...Do I feel like it still has a decent amount of power? Yes, but that could be due to the custom exhaust, stage 2 chip and CAI.

I don't feel bogged down when I am in mud and with even the slighest moisture on the ground I can get em spinning a little. I just ran a 0-60 test with my Edge Evolution for the purpose of this thread with my best time @ 11.17 I actually did get the tires spinning off the line which kind of suprised me a little...must be some road salt on there or something cuz the pavement was dry as a bone. Before I upgraded to the 35's I was running 285x70x17 mastercrafft courser ct's (for sale btw) and ran a 7.98 but averaged mid to high 8's on time.

 

go 4.56 definately, i did and get 18 mpg across the board, im only runnin 34" with a level kit. but im a V6.

 

The reason i asked you the Number 5 question is... If you plan on going with a bigger tire then you might as well gear for it now or wait and gear later. Dont regear twice its too expensive. Well at least for me.

Id honestly say with what you have told me then 4.56 would be just what you need.

Did you ever recalibrate your speedo for the oversized tires? if not then your 0-60 would be alittle less. Cause in actuality you would be hitting 60 when the needle hits around 50.

 

Yeah here is another vote for 4:56, 4:88 is too much for 35's.

 

i vote 4.88's. difference is very little in rpms and mpg's. Launch is really nice. If you are looking at 4.56 for your truck with 35's and even have a faint thought of going bigger, do it now. you wont regret it. If you have any questions, i have them in my truck

 

With 35" tires you will be turning this many RPMs at each speed (in OD with the TC locked):

60 mph-
4.10s: 1653
4.56s: 1839
4.88s: 1968

70 mph-
4.10s: 1929
4.56s: 2145
4.88s: 2296

80 mph-
4.10s: 2204
4.56s: 2451
4.88s: 2623

Like I said 4.10s will be about where you were with stock tires. If all you are looking for is improved fuel economy and less stress on your tranny, and a more stock gear ratio, go with them

4.56s would give good performance and sacrifice a little bit of mileage. It would be comparable to having 4.10s on stock tires. They get my vote.

4.88s are going to be too much, IMO, unless your driving is 90% city. You'd get a ton of low end power, but you're turning a lot of RPMs on the highway.

 

keep in mind that much of the performance mustang crowd turns their tiny *** street tires w/ 4.10's! If you are thinking of regearing, do at least 4.56, if not 4.88. i once feared the lower gearing, but came to the realization that if you're going to shell out the money for the job, do it right, and go lower.

 

Just for the record i did not say, if that was me anyway,- "youll blow up your trans" it won't blow up your trans but it will biuld alot of heat in your trans and make your motor work and if your going to be toating that boat around then yes maybe i do agree with that its going to put a serious hurting on your trans. 3500lb trailer may be a bit of an exageration but cetaintly like driving w/ a 2000lb trailer behind you. 4.56's maybe the right gear for you, coming form an offroad standpoint 4.88's with out a doubt. coming form a strictly road point of view 4.56's.

the chart posted seems accurate and most heplfull, i did not check it but for me at 60mph with TC locked up i would like to be running in the 1800rpm range which would put you at 4.56's w/ 4.10 at 80 chart says 2200 hell with any type of load your tranny will still probably wanna downshift at 80. your truck should have came w/ 3.73's or 4.10's form the factory.