SCT Tire Size Adjustment Doesn't Seem To Work?

[LTRMC02]

I've recently changed tire size which in turn cause error in my speedo reading. It was reading near dead on comparing to my GPS but now has about an 8% error. I have a custom tune and when it asked to change options then I chose that and changed the Revs\Mile to what matched my wheel size. This had no effect on the speedo error so I then changed the Revs\Mile by 50 and it still had no affect on the speedo

Am I going about it wong or can you not adjust these options off of a custom tune?

[Dave]

Adjusting revs per mile only changes shift points. It has no effect on your speedometer.


Return it to stock unlock your tuner and take it to the dealer. They can adjust your speedo for about 40 bucks

[LTRMC02]

Originally Posted by Dave

Adjusting revs per mile only changes shift points. It has no effect on your speedometer.


Return it to stock unlock your tuner and take it to the dealer. They can adjust your speedo for about 40 bucks

Serious? And the whole time I thought I had the capability of correcting speedo error I believe I was able to do that on my chevy 1\2 ton with a hypertech? That sucks, I was planning on having two sets of wheels and using the smaller ones when towing on an extended trip so I'll just have to figure in error I guess. Man I sure thought that was a perk of having the SCT.

[Matt@SCT]

Originally Posted by LTRMC02

Serious? And the whole time I thought I had the capability of correcting speedo error I believe I was able to do that on my chevy 1\2 ton with a hypertech? That sucks, I was planning on having two sets of wheels and using the smaller ones when towing on an extended trip so I'll just have to figure in error I guess. Man I sure thought that was a perk of having the SCT.

What device do you have?

[mustangman02232]

my truck has 4.10 gears, going from 265-75r16 (31") to 285-75r16(33") i now have the equivalent of 3.73s, reprogramed my truck as having so and my speedo is now dead on,

once i get my SRL cant i have it written into the tune for the proper tire size?

[LTRMC02]

Originally Posted by Matt@SCT

What device do you have?

I don't really know as my SCT doesn't have the X3 or SF3 on the front of it? I think the model # was 3000 and it does say custom flash on the bottom of it. I just bought it new from MKM Customs back in November.

[PGreenSVT]

You can change it with Autoenginuity.

[kenny7231]

How much does the auto engunity cost?

[Lilpooh]

Originally Posted by kenny7231

How much does the auto engunity cost?

Raul at Stealth Diesel has it for $359, Total Ford Bundle with ProLine connector.

[LTRMC02]

Originally Posted by Lilpooh

Raul at Stealth Diesel has it for $359, Total Ford Bundle with ProLine connector.

I hope it does more than just allow speedo correction for that price? Anything else on the market that can just correct you speedo for less money? Still find it hard to believe that didn't put in that option, , as you know tire size changes are usually one of the most common mods done on a truck.