Quote:
Originally Posted by Trap63
Hi guys, I ask you all to help me to clarify what’s legal or not (road legal I mean) in US about car modifications.
When we discuss in Italy, mostly in Europe too, we believe here that US rules help owners to modify car setup with no long and complex procedures.
I think that we are a bit influenced by “Gas Monkey Garage” where we see any kind of modifications that let us to think that US are the Paradise on earth.
Each one of us desire to be Richard Rawlings.
Some Euro examples:
- Wheel, on our car paper issued by National Motor Bureau of Transportation the constructor specifies the measures of ET, Size of rims. BMW and Mercedes-Benz usually specify several measures from 17” up to 20” on same model. Subaru not. In Europe the only road legal measure of rims are 17x7 ET.
- Tyre, the measure of the tyres are on paper, i.g 215/45 R17 for BRZ
Only in Germany if a rims is TUV certified might be installed with no need of test, in Italy you cannot. You need a certified set of rims for that vehicle, i.g. OZ Wheels for BRZ on 18” (18x8 ET45, 5x100) to install 225/40 R18 and later you drive to Motor Bureau to pass test. Since July of last year the new paper of National Bureau reports the ET measurements too.
|
Here in the US, we can use nearly any wheel and tire as long as it can physically fit on the vehicle. We have no government rules outlining what wheel specs or what size, load rating, and speed rating we can use on our tires.
Trucks are the worst offenders, many heavy duty trucks may call for a 245/75 16 120R. In order to look more "badass" truck owners will put 18, 20, or 22 inch wheels and, let's say tires with specs 305/40 22 114V on their trucks with no regards to the recommended load or speed rating. And there really aren't any laws in the US stating that they can't do that.
The company I work for is owned by a parent company in France and my colleagues there have told me that it is much more strict and the wheels / tire specs that are on the door card are the only wheels / tires that are allowed on the vehicle, and using anything different needs government inspection and approval as well as in Italy.
Another example is my FR-S, the door card says that the OE tire is a 215/45 17 87W, so in Europe that is pretty much the only tire you can use. In the US, you can buy nearly any size tire for the car as long as it can fit and places like Tirerack will happily sell you a 225/45 17 91V to put on the OE wheels. I run 225s for autocross / track day events and there's nothing stopping me from running those tires on the street.
Also, the door cards for many European brands such as Mercedes or BMW may only show the tire on the car and not the other possible tire options like it does in Europe. I know some BMW door cards may have 4 or 5 different wheel and tire specs with several recommended tire pressure specs for highway travel or carrying loads. In the US, there's none of that extra information, for example my E90 330i only had specs for the original wheels and tires and did not include the load or speed rating. Our laws regarding vehicle modifications and especially wheel and tires are much less strict, or just don't exist.
Hope that gives you some more information
