NASCAR FAQs

[nascar123]

I'm new to NASCAR and am seeing a lot about how race mpg is around 4-5. Does anybody know if this has changed over time? I know that they switched from leaded to unleaded fuel in 2007 - wondering what it was like before that change. Thanks!

[Adam43]

I suspect that it has been similar for many a year, but I will be happy to be corrected.

I bet the bigger change might have come when they went to fuel injection from carbs in 2012.

[broadrun96]

It's barely fuel injection as we know it now. I think they have a similar setup my old Suburban had from the early 90s. It looks like a carb but is electronically controlled, and they still use restrictor plates at Daytona and Talladega instead of a tune. I've seen it reported they couldn't detune enough to make it worth it. Uses McLaren electronics, I'm guessing Lucas was not available for the contract.

[fieldodreams79]

Fuel mileage used to be dependent on how big your "tank" was:

https://www.carthrottle.com/post/7-h...rk-of-one-man/

Smokey might have lived in the grey area of the rule book, but he always maintained that he followed the rules when they were clear. As such, when the size of the fuel tank became regulated in Nascar, Smokey duly obliged by installing a regulation-sized fuel tank.

However, there was no regulation on the size of the fuel line. Obviously, it didn’t take Smokey very long to capitalize on that non-rule. He made a fuel line that was two inches wide and 11 feet long, closer in dimension to an anaconda than a fuel line. Although it sounds pretty funny, the monster fuel line held an extra 5 gallons of gasoline, which made a very real difference on the track (until it was banned, of course).

One of Smokey’s most well-known incidents involved shoving an inflated basketball into an oversized fuel tank before the car was inspected by scrutineers. When they filled the tank up with fuel, the tank would appear to conform to regulations. After passing inspection, Smokey would then deflate the ball, pull it out of the tank, and fill the regulation-plus-basketball-sized fuel tank for the race. Amazingly, nothing in the rules at the time said this was illegal.

[broadrun96]

Good ole Smokey, with all due respect to everyone thinking Penske reads the rules and knows every inch of the book, he knew EVERY rule and everything that wasn't banned