I recently asked if the shift points on our transmissions could be change without adjusting for my new tire diameter and received a lot of negative feedback about Odometer fraud. Lets look at what has changed and how it is fraud.
With my new tires, only the surface that hits the road has changed which allows me to travel a greater distance in one rotation of my rear axle. The odometer records the same as stock so the parts on my vehicle that will wear out have not rotated any more than what has been recorded on my odometer. The stock tires rotate 638.1 times per mile and the new tires rotate a total of 586.93 times in one mile. I just traveled further in the same amount of rotation. This has effectively changed my final drive ratio to a 3.74 rear end.
Dodge offers 4 different rear ends and this is how this effects the wear on the engine.

The following number are calculated in the final gear only.
4.56 rear end has a final drive ratio of 3.15 in overdrive-The engine has made 2010.01 rotations per mile. The axle has made the same rotations because the tires are all the same.
4.10 rear end has a final drive ratio of 2.83 in overdrive-The engine has made 1805.82 rotations per mile. The axle has made the same rotations because the tires are all the same.
3.90 rear end has a final drive ratio of 2.69 in overdrive-The engine has made 1716.48 rotations per mile. The axle has made the same rotations because the tires are all the same.
3.54 rear end has a final drive ratio of 2.44 in overdrive-The engine has made 1556.96 rotations per mile. The axle has made the same rotations because the tires are all the same.

With my new tires my engine makes 1661.0 rotations per mile, which is more than a 3.54 rear end and less than a 3.9 rear end but my axle has turned less times due to the bigger tires so there is less wear on my rear end.
If I have my truck recalibrated for the new tires I have in effect shortened my warrenty period by 8.72%.

 

Yep! That is generally what a modification to the vehicle stock configuration does.

 

wow... that is some interesting logic...

 

WorldCom and Enron called it creative financing .

 

WOW!! How wild is that! Why would you not just have the rotations/mile adjusted so that your speedo is correct. I would think it could have been done in half the time it took to figure out that interesting math problem. Then you would not have to worry about your shift points b/c they would be correct and your speedo/odometer would always read correct.

 

 

 

That was a good

 

Odometer fraud is a violation of both state and federal law (felony), and has nothing to do with your warranty, (unless you changed it to keep your vehicle in warranty). I don't believe the fact that you have oversized tires on your vehicle would be considered odometer fraud unless you did it, to try to keep the mileage low. Modifications of the vehicle is what can restrict your warranty, and it sounds like you've already done that.
I'm not trying to judge here, the tires on my vehicle are larger than the OEM tire also. As long as you disclose that when you sell the vehicle there is no violation.

 

Your warranty is based on the number of miles your vehicle travels or the time it is in service. NOT the number of revolutions your axle makes. There is a lot more to it than just how many times your tires go around or engine turns over. Road vibration, exposure to elements, time you spend in the vehicle, loads you haul etc.

Just do the right thing and get the speedo adjusted.

 

But I just think of how many 4x4 trucks out there that have lifts with bigger tires who don't even know to change the speedo. My father in law never heard of it until I told him about it and he's had 4x4 vehicles for a while. I'm sure all of these guys are just figuring the big drop in MPG as the cost of the lift/tires not knowing that their spedometer isn't correct.

 

Bigger tires is not odo fraud. The law is in place to keep people from turning the odo back, and if you indeed did this there is a check box on the title that you can mark for inacurate mileage.
My wifes Toyota is bone stock, and her speedo reads 2mph faster than the car acutally travels at 25 mph. This equates to 10% more miles than is actally on the vehicle, so her 100k warranty will be up at 90k. Is this odo fraud?
DK

 

Well, yes, kind of. But on Toys part. If your speedo is off, you need to take it back and have them recalibrate it. But, is it off at all speeds? Take it out to a measured mile and clock in against that. Or a GPS if you have one. But, yes, Toyota will have to fix that.

Bigger tires would be odo fraud if you didn't disclose that the miles on the odometer aren't the actual miles on the vehicle. So, in your wife's case, you'd have to check that block if you were to sell the vehicle saying that the mileage indicated is inaccurate. That would make the value of the vehicle go down quite a bit, of course. That block isn't there for people who have rolled an odo back, it's there for bigger (or smaller) tires, replaced odos, defective or inop odos etc. The block says the odometer mileage isn't the actual mileage. For whatever reason.