Power & speed difference THAT noticeable going from 30s-31s?

[ACBlessing]

Hi all.

I'm wanting to go from my stock P255-70-16s to LT265-75-16 (or maybe larger) but already the 265s are 1.6 inches taller than stock...I'm just going for the slight lift (torsion bars/shackles/tires) and not the 33s and 35s that look good on your trucks.

My questions are:

1. How much of a difference in power will I notice going up 1.6 inches?

2. Any other concerns going up in tire sizes i.e. shift points, etc.?

Sorry to sound so elementary about it but I'm new to this (and I'll never go back ;-) ) Please help with any and all tips, no matter how basic you think they are. I really would appreciate it.

Thank you, -AC

 

[914x4sport]

I dont think youll have a problem especially with the V8..Do you know your axle code and/or gear ratio?

 

[ACBlessing]

No, I don't. Are you talking about maybe getting a different gear for the speedo correction?

 

[Robert]

When I went from the 255 70R16 Firestones to my 265 75R16 Michelin LTX ATs, I could detect a slight drop in acceleration off the line. I have the SOHC V6 so you may not notice as much of a drop as I did with your V8. It is by no means bad, and with my Borla, K&N FIPK & Superchip, I have gained a lot more than I initially lost with the taller tires. Incidentally, with my 265 tires and my factory 4.10 axle, it equals the same overall ratio as 235 75R15 tires with a 3.73 axle which is a very common overall ratio offered by Ford. Finally, my speedometer was about 3-4 MPH off at highway speed. I had to change my speedometer gear by one tooth to get it to match my GPS again. Unfortunately, you don't have a gear to change on your 2000. The only way to change yours is by finding a Ford Service department willing to reprogram your computer for about $75. Ask GJarret for details. He already went through it.

 

[914x4sport]

Originally posted by ACBlessing
No, I don't. Are you talking about maybe getting a different gear for the speedo correction?

No i meant the gear ratio at your differential....Its probably a 4.10 though...behind the V8 it should be at least that...

 

[ACBlessing]

Thanks Robert.

I'm bummed about the lack of speedo gear but on the bight side, I know a couple of Ford mechanics from the bar who happen to work at the dealership I bought my MM from. With enough beer.........hmm. I'm a little leary about having my puter reprogrammed without them giving me the new code for the superchip so I'll make sure to get it.

I've got the KKM to put in this weekend and then next month comes the exhaust and hopefully superchip. Glad to know there's not THAT MUCH of a difference, and you're right that it should be lessened by the V8 but I will make the same mods you did and that should make up for it.

Normally, I drive like a granny around here but sometimes I just need to pass some a$$hole who keeps getting in and out of my lane and other circumstances when I need some power to get into an exit lane or just to humiliate Honda pukes. It's funny that with their rat-trap mufflers and Japanese stickers on the windshields of their lowered Accords that they still lag off the green light...furiously shifting gears trying to pass me. I'm not even racing and the V8 is wonderful. Sorry about getting off on a tangent.

I just want a little more height and a little more power (for my rig).

-AC

 

[jerry989]

thats funny i wemt from 235's to 31.50-10.5's and now my speedo is dead on ! go figure ? before the speedo was off by about 6 kph ford was cheating me on the warranty !

 

[yob_yeknom]

my experience

1. How much of a difference in power will I notice going up 1.6 inches?
Probably hardly any at all. I went from 235's to 31's with a V6 and 3.55 gears. I didn't notice much difference and you should be a lot better off than me.

2. Any other concerns going up in tire sizes i.e. shift points, etc.?
My tranny shifts a lot more now between 3rd and OD. It is driving me nuts. I'm hoping calibrating the speedo so it will know how fast it is really going will help.