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So is there still not much I can do to recalculate the odo or mph ...to my new tires ..o well..
I recalibrated mine with a hypertech unit, info in my build thread. Not sure if it works for later model FJs, mine is an '09.

Good Luck,
Shawn
 

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I recalibrated mine with a hypertech unit, info in my build thread. Not sure if it works for later model FJs, mine is an '09.

Good Luck,
Shawn
Sweet ya when I searched old stuff came up so im glad hypertech came out with something ..mines a 13'
 

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I just use the speedo on my GPS to keep me in check. Even when the speedo reads 80, the GPS shows 84, so they aren't far enough apart for me to worry about.
 

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I just use the speedo on my GPS to keep me in check. Even when the speedo reads 80, the GPS shows 84, so they aren't far enough apart for me to worry about.
My concern mostly is when or if I sell.. I can be honest about actually mileage on fj..
 

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So I'm concerned about this also and getting new wheels and tires installed this friday. I searched online and the ones I see for adjusting or reprogramming/ intercepting signals all say 2007-2010

My question what is the difference between 2010 and 2014 (mine). I don't believe there to be much difference in many areas, same engine, transmission.

Is the ECU different or speed sensor different? If not then shouldn't the 2010 model hypertech and others still work on a 2010+ model like my 2014?

How does the 305/ 65 R18 which per the below link is 2" taller tire (width shouldn't impact) impact my odometer.

265/70-R17 vs 305/65-R18 Tire Comparison - Tire Size Calculator

Shows I will be running 1-4mph faster from 20-65mph reading per that site. How does that affect my mileage will I be showing more than I actually travel or less?

Sorry newbie to this stuff.
 

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Running 285's & my GPS shows the speed o is now correct.
 

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So I'm concerned about this also and getting new wheels and tires installed this friday. I searched online and the ones I see for adjusting or reprogramming/ intercepting signals all say 2007-2010

My question what is the difference between 2010 and 2014 (mine). I don't believe there to be much difference in many areas, same engine, transmission.

Is the ECU different or speed sensor different? If not then shouldn't the 2010 model hypertech and others still work on a 2010+ model like my 2014?

How does the 305/ 65 R18 which per the below link is 2" taller tire (width shouldn't impact) impact my odometer.

265/70-R17 vs 305/65-R18 Tire Comparison - Tire Size Calculator

Shows I will be running 1-4mph faster from 20-65mph reading per that site. How does that affect my mileage will I be showing more than I actually travel or less?

Sorry newbie to this stuff.
When you go to a larger tire, you cover more ground per revolution. If the speedo isn't calibrated correctly, you'll be going faster than the speedo says. The problem is knowing how much. The factory speedometer on factory tires reads low typically, so most guys running 285 or 305 tires are usually getting a more accurate reading than stock without needing to adjust something. I'm running 315s and I find I'm running about 3mph over at 60mph.

I see you're in Kernersville (I work in K-ville) so keep a lookout for the little trailers they put out that flash your speed as you go by. I usually use those to gauge how close my speedo is. I'll cruise by at a steady 40mph, and if it reads 42, then I know my speedo is off 1mph for every 20mph that I'm cruising. I'll extrapolate that to know that I'm running 63 at an indicated 60 or 84 at an indicated 80.

I'm perfectly fine with my speedo off since I usually cruise a few mph over the limit. If the speed limit is 45, I just go 45 according to my speedo. I could care less about mileage being off since I'm gonna drive this thing into the ground.

Oh, if you have larger tires, you're odometer is accumulating less miles than you're actually traveling.
 

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I use this Hypertech’s In-line Speedometer Calibrator Module Speedometer Calibrator - Hypertech when i put my 35s on, remove it when i put my winter tires which are 33s.
 

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I didn't see this mentioned anywhere in the thread, but you guys that are using GPS speedos are aware that the GPS speed reading is only accurate on a completely flat road right?
 

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I didn't see this mentioned anywhere in the thread, but you guys that are using GPS speedos are aware that the GPS speed reading is only accurate on a completely flat road right?
Oh my God, are you implying there are three dimensions??? :rofl::rofl:

Luckily, it's such a minimal factor that it's close enough for most. Even a 400' elevation change in a mile is throwing off the numbers by less than .3% Around here, that's about as bad as we'll get. Of course, in the higher mountains, it is more of an issue.
 

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Oh my God, are you implying there are three dimensions??? :rofl::rofl:

Luckily, it's such a minimal factor that it's close enough for most. Even a 400' elevation change in a mile is throwing off the numbers by less than .3% Around here, that's about as bad as we'll get. Of course, in the higher mountains, it is more of an issue.
Haha, I have a biased view of the world, since I regularly drive on roads with grades above 6%. But I guess FJ owners in Kansas would never have any issue with GPS speed being inaccurate :rofl:
 

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Keep in mind the speedo reading and odometer reading are calibrated separately. This is why a post above said the speedo reads correct with larger tyres but the odo is reading lower than with stock tyre size. For legal reasons this is what we have (with OEM tyres speedo reads high to keep you in check, odo reads correct to keep the lawsuits at bay).

My 2007 reads all over the place, sometimes high, sometimes low, sometimes correct (according to the GPS), varying by speed. Not very inspiring. I'm using a Garmin Montana as the unit is set to output to my APRS radio (Kenwood D-710) for position and speed for those who want to watch me. ;)
 

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When you go to a larger tire, you cover more ground per revolution. If the speedo isn't calibrated correctly, you'll be going faster than the speedo says. The problem is knowing how much. The factory speedometer on factory tires reads low typically, so most guys running 285 or 305 tires are usually getting a more accurate reading than stock without needing to adjust something. I'm running 315s and I find I'm running about 3mph over at 60mph.

I see you're in Kernersville (I work in K-ville) so keep a lookout for the little trailers they put out that flash your speed as you go by. I usually use those to gauge how close my speedo is. I'll cruise by at a steady 40mph, and if it reads 42, then I know my speedo is off 1mph for every 20mph that I'm cruising. I'll extrapolate that to know that I'm running 63 at an indicated 60 or 84 at an indicated 80.

I'm perfectly fine with my speedo off since I usually cruise a few mph over the limit. If the speed limit is 45, I just go 45 according to my speedo. I could care less about mileage being off since I'm gonna drive this thing into the ground.

Oh, if you have larger tires, you're odometer is accumulating less miles than you're actually traveling.
Yeah I was hoping for that or else my MPG got killed, lol. I got about 14.5-15.5 MPG vs. average of 18.5MPG. But then again it seems to do worse on the highway than in town driving.

yes I'm in K'vegas, outside edge Winston side anyway. I'll look out for it/ them, and check it. I just don't want to be clocking more miles than I'm going as its a 2014 and full factory warranties are still in effect. I kept stock wheels and tires for when services are due or I take it in for service.

Nothing wrong with extending warranty a little bit :grin
 
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