speedometer correction
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When I got the larger tires my dealer reprogrammed it for me. He had the tire size and manufacture in the starscan tool. it took about 5 minutes, but I thought I heard the dealership could only adjust up to 33" so you'll need to check.
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10,174 Posts
Nope, VIN locked.
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26,034 Posts
Either buy a programmer or go to the dealer for about $120 bucks and have it flashed...:w:
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596 Posts
I've got an Edge Juice w/Attitude, but currently have stock sized tires so I haven't messed with that adjustment. Will it correct the dash speedo if you make a tire diameter change? That'd be great since I eventually plan on putting taller tires on it!
I realize the Edge unit can display speed, but I'd rather not use up one of my four display quadrants for that. I'd rather get my speedo re-calibrated at the dealer...
Tommy
I realize the Edge unit can display speed, but I'd rather not use up one of my four display quadrants for that. I'd rather get my speedo re-calibrated at the dealer...
Tommy
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My ScanGauge II can be calibrated for oversized tires and report corrected speeds... :thumbsupI've got an Edge Juice w/Attitude, but currently have stock sized tires so I haven't messed with that adjustment. Will it correct the dash speedo if you make a tire diameter change? That'd be great since I eventually plan on putting taller tires on it!
I realize the Edge unit can display speed, but I'd rather not use up one of my four display quadrants for that. I'd rather get my speedo re-calibrated at the dealer...
Tommy
But you'll find out the larger tires will kill your MPG.
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570 Posts
Odd. Mine will (model 3705 with software version 1.04). I am not too fond of its piecewise linear tunes and it is a little flaky when it comes to clearing codes but I have confirmed the speedometer correction in all three tunes with my GPS over a long period with the cruise control set on the interstate.
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596 Posts
Well, my Edge can display corrected speeds, but I want my speedometer to display correctly (for a variety of reasons). I didn't think the Edge could control the speedometer, but thought I'd ask.
Yeah, bigger tires kill mileage, but I'm only planning on 33's to 34's, nothing "big" and certainly not a mud terrain (which kill mileage even worse). I'll certainly run smaller tires than what's on my Jeep.
Tommy
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As for me I'm head down in size next set... I'm going to aim for a 235/85 R16 which is still a 31 inch tire but it will be 5 pounds less in weight roughly and 1-2" inches narrower... :w:Well, my Edge can display corrected speeds, but I want my speedometer to display correctly (for a variety of reasons). I didn't think the Edge could control the speedometer, but thought I'd ask.
The only thing I know for sure that works is going to the dealer for a flash, Smarty, or SuperChips programmers...
Yeah, bigger tires kill mileage, but I'm only planning on 33's to 34's, nothing "big" and certainly not a mud terrain (which kill mileage even worse). I'll certainly run smaller tires than what's on my Jeep.
Trust me you'll see a difference... Like myself I've got a set of Cooper STT (265/75 R16) and my stock set of Michellin's (265/75 R16). Just the weight difference between the Cooper STT and the Michellin's is about 20 Pound per tire. But that amounted to +2 MPG gain switching back to the Michellins for the summer over the Cooper's...
Now couple the size change (rolling resistance) and weight of the tire it will show... There is no way to cheat physics
Tommy
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596 Posts
I didn't realize the Coopers were to portly! So far I'm pretty content with my Michelins, but they do seem to chunk very easily. Not too happy about that and if I'd been the poor sap to spend so much money on them, I wouldn't be too happy about it.
I'm not trying to cheat physics (engineers should know better!). I realize the tire size I think I eventually want to run will cost me a bit in mileage, but that's okay. It's not my daily driver.
A 235? That'll surely net you more mpg. I'll stick with a bigger tire footprint, though. I like to stop when I need to.
Tommy
I'm not trying to cheat physics (engineers should know better!). I realize the tire size I think I eventually want to run will cost me a bit in mileage, but that's okay. It's not my daily driver.
A 235? That'll surely net you more mpg. I'll stick with a bigger tire footprint, though. I like to stop when I need to.
Tommy
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26,034 Posts
Just for the MPG math...
Say your getting 19 currently... Then changed tire and dropped -1 MPG to 18 MPG... Today's price of diesel in Riggins, ID is $4.889.
19 MPG * 35 Gallon Tank = 665 Miles
18 MPG * 35 Gallon Tank = 630 Miles
665 Miles - 630 Miles = 35 miles difference in one tank... Pretty small...
But in one year I travel roughly 25K miles.
25K / 19 MPG = 1,315 Gallons of fuel
25K / 18 MPG = 1,388 Gallons of fuel
$4.889 * 1,315 = $6,429
$4.889 * 1,388 = $6,785
$6,785 - $6,429 = $356 more fuel consumed a year for larger tires...
So for every MPG loss in my example you lose quite a bit...
Just a quicky of my stock MPG to my enhanced MPG...
25K / 17.5 MPG = 1,482 Gallons a year
25K / 23.3 MPG = 1,072 Gallons a year
1,482 * $4.889 = $7,245
1,072 * $4.889 = $5,241
Total saving a year... $2,004... just buy looking for the MPG!!!
Say your getting 19 currently... Then changed tire and dropped -1 MPG to 18 MPG... Today's price of diesel in Riggins, ID is $4.889.
19 MPG * 35 Gallon Tank = 665 Miles
18 MPG * 35 Gallon Tank = 630 Miles
665 Miles - 630 Miles = 35 miles difference in one tank... Pretty small...
But in one year I travel roughly 25K miles.
25K / 19 MPG = 1,315 Gallons of fuel
25K / 18 MPG = 1,388 Gallons of fuel
$4.889 * 1,315 = $6,429
$4.889 * 1,388 = $6,785
$6,785 - $6,429 = $356 more fuel consumed a year for larger tires...
So for every MPG loss in my example you lose quite a bit...
Just a quicky of my stock MPG to my enhanced MPG...
25K / 17.5 MPG = 1,482 Gallons a year
25K / 23.3 MPG = 1,072 Gallons a year
1,482 * $4.889 = $7,245
1,072 * $4.889 = $5,241
Total saving a year... $2,004... just buy looking for the MPG!!!
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2,237 Posts
Not bashing here, but that's worth it to me. Last stat I heard, the average american drives a little less than 15,000 miles per year, so most peoples fuel cost would be less. If I wanted small tires I would get a car, i'm going 35's next on mine and I expect to see the mpg's drop and the looks and comments go up :thumbsup But this is coming from a guy that doesn't understand why in the world they make 2wd trucks
just my .02-Joe-
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331 Posts
I care about the mileage I get, but not enough to change my tire size back to 235/85 r 16. I still get the instant display to hit 22 on the highway(even with the speedo being 7-9 mph slow). Besides, if I really wanted a gas saver---I'd go buy a little car! I just don
t want to have to guess at the speed I'm going.
Also: The dealer can't program for 37" tires----the post earlier was correct, 33" and smaller is what the local dodge dealer said he could flash for. As a joke(I HOPE) he said at least it would get me closer to being right!!!!!!LMAO!!!!!
t want to have to guess at the speed I'm going.
Also: The dealer can't program for 37" tires----the post earlier was correct, 33" and smaller is what the local dodge dealer said he could flash for. As a joke(I HOPE) he said at least it would get me closer to being right!!!!!!LMAO!!!!!
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