Project QX4 MPG is go!

[KyooX4]

Holy crap, V8s aren't legal in CA?!? What kind of commie crap is that?

[K03sport]

Holy crap, V8s aren't legal in CA?!? What kind of commie crap is that?

V8s aren't illegal in CA. The problem has to do with the platform. The R50 never came with a V8 as an option, so it is illegal to put a motor that did not come in the car originally and pass thier visual/smog inspection thingie.

While we are talking MPG...just did a 2200 round trip to TX and despite horrible weather, wet roads and head winds, we averaged 22mpg on the way there and 21mpg (carried about 400lbs more stuff) on the way back.

Ran 89 octane the whole time and tried to keep speeds at 70 or 65 depending on speed limit. Some of the heavy rain had me down in the 50s due to visibility, but that didn't last for more than an hour or two.

Getting the engine to return better (more) mpg is all about making its process of combustion as efficient as possible. Less restriction in, a more complete burn cycle, and easy flow out will all have an effect. However, there is only soo much one can do. Ironically, more air also means more fuel in order to keep the right fuel/air mix and that is all up to the ECU.

Running lean might save fuel, but it will make the cylinders run hotter and cause possible damage (think racecar running lean then "melting" the engine). Running rich might make the engine run cooler, but there is too much fuel to burn properly and there really isn't that much of a power gain plus you get the nasty black tail pipe soot.

Power and economy is a difficult balancing act. The R50 can only be so economical due to its weight, engine and frontal area. Super skinny tires, gutted interior, light foot, etc. isn't really the way to go. Your best bet is to just drive sensibly. I'm not talking about hypermilling, but just simple things like driving the limit and not over it, easy starts keeping revs below 3k, coasting a bit more to stops and red lights and possibly time the red so it turns green when you get there, minimize going 0mph with the engine running (avoiding drive thrus).

Now that winter in soon upon us, that means winter gas is just around the corner. So, expect your summer mpg numbers to go down about 10%-15%.