I topped her out today but not without some questions. At 110mph it hit the speedlimiter. Nissan has these set for 114mph. It makes me wonder if all 3 tire sizes, that the trucks come with, are calibrated the same in the ECM. Next weekend I'm going to hook up my mobile GPS unit to my laptop and see if there is any error in the speedometer.

Granted the 4mph discrepency is less then 4%, of which I'm sure is an industry accepted allowance, but it does make me wonder if all the trucks are calibrated exactly the same irregardless of tire size. Has anyone else noticed this? My other truck with the 18's would top out at an indicated 115mph before it hit the speedlimiter.

You are wayyyyyyyyyy beyond this dumb truckers capabilities on this one! :?

I topped her out today but not without some questions. At 110mph it hit the speedlimiter. Nissan has these set for 114mph. It makes me wonder if all 3 tire sizes, that the trucks come with, are calibrated the same in the ECM. Next weekend I'm going to hook up my mobile GPS unit to my laptop and see if there is any error in the speedometer.

Granted the 4mph discrepency is less then 4%, of which I'm sure is an industry accepted allowance, but it does make me wonder if all the trucks are calibrated exactly the same irregardless of tire size. Has anyone else noticed this? My other truck with the 18's would top out at an indicated 115mph before it hit the speedlimiter.

110? Hmm I hit 115 in my SE and it was still pulling. But normally SE's on Nissans usually have a higher speed limiter.

I haven't hit the speed limiter in my Titan yet, but I have had her up to an indicated 110 and my gps said I was doing 116. I was using my GPS for a while to get a better MPG rating. I would usually get about 300 miles on the odo and the gps would read anywhere from 325-330. I'd like it to be a little more accurate but I'm pretty sure that it is well within the accepted standard for speedometers.

I haven't hit the speed limiter in my Titan yet, but I have had her up to an indicated 110 and my gps said I was doing 116. I was using my GPS for a while to get a better MPG rating. I would usually get about 300 miles on the odo and the gps would read anywhere from 325-330. I'd like it to be a little more accurate but I'm pretty sure that it is well within the accepted standard for speedometers.

My thoughts exactly. I'll have to do some more research as to how Nissan is calibrating the speedometers in these trucks.

Hey Jet, how many RPM's were you turnin' at 110 MPH? Just curious as to how much top end you had left in her. Once HyperTech produces a Power Programmer for the Titan, I'd like to see if my V-rated tires will actually handle 149 MPH :!:

I checked mine on a GPS when I first got it and if I remember correctly (I'm not sure I do, but anyway) at 70 MPH on the speedometer the GPS registered around 74 MPH. Or maybe it was the other way around??? Anyway, I know it was not accurate.

I have the "Off Road" and I figured it was the tire size that made the reading off.

As a AAA member, I can have my speedometer checked for free when their mobile testing unit comes to an AAA office near me. Usually, I check my vehicle's calibration when it is smog cheked, but the Titan will not need this for a few more years since it is new.