Where to find statement allowing 48in extension of your car for fuel economy?
 

I have read in a hand full of post indicating the DOT or EPA or other gov't agency allowing you to extend your car's rear end by 48 inches, but I can't seem to google up the supporting information for such a claim. I am considering taking the leap in modding my Saturn SL2's rear end. Just trying to find some info in the event that I need to defend myself from a ticket.


Thanks in advance.

I wonder if Europe has anything similar?

It depends from country to country I think there's no general regulation in the EU regarding cars except having high taxes on fuel :D / emission standards

I don't know of any reason you can't make your car 3 feet longer, 4 feet longer and you would need a red flag in the day time and a red light at night, just like if you carried lumber with it sticking out the back of your car, but as long as all safety devices are still intact, like bumpers, lights, you should be fine, for them to give you a ticket they have to find the law that you broke as well and if you do get pulled over and offer to modify or remove anything that they feel is a true danger they should let it slide and you will learn.

If you built lights and a license plate mount into the extension, it can be considered a permanant part of your car when mounted and exempt from any red flag/red light regulations. My boattail itself has never raised any concerns with the police in any of my traffic stops, just the location of the license plate mounted on it (has to be at the back of the vehicle) and the clear lexan covering I originally had over the plate.

In Oklahoma you would have to have the vehicle under the maximum length limit for a 2 axle vehicle but that is likely to be many feet longer than you would want anyway, and you will have to move your lights and tag to the rear most part of the car. Additionally it must look (and BE) safe. Other than that as long as you have rear view mirrors as are required and nothing looks like it is going to fall off and hurt something you should be fine. Your tag must be well lit and not covered by anything as well.

Thanks for the helpful replies. Hopefully this will help me break through 50 mpg for an automatic transmission (non-hybrid), something I have not seen yet.

TBH I'm happy with fuel taxes, emissions limits seem useless to me.

The real enemy of mods of any kind, including ecomods is your insurance in Europe. Anything you change has to be passed on to your insurance company for approval. In fact anything modified from standard when you buy the car has to be passed to your insurance to be covered otherwise they will try and avoid any liability and leave you uninsured - which is of course illegal as well, at least in the UK.

As long as your insurance company is happy then safety tests (e.g. UK MOT) will only test for basic safety such as rust and pedestrian safetty on aero mods (e.g. any sharp edges on bodywork) but will probably leave anything else alone. If this was not the case then Andy Saunders couldn't get an MOT for the Stratos Zero car amongst other cool (and less cool) creations

http://www.mcdowellcrook.com/blog/wp...ratos-Zero.jpg

Having now tapped this I'm wondering about any mods in Europe, or at least the UK in terms of insurance.

...now I like the looks of that metallic-copper colored car!

...but, gotta question those indented side-scoops-wingy things.

I'm assuming that the car is a rear engine car so that is for an intake and cooling. Only real changes that I would make to the body is flare the front bottom out to push the air away from the wheels and add do the same a little just before the rear wheels. I might think about dropping the line a little slower at the intake and blending it in with a slight inward curve (shaped like half of a ying-yang).