i recently installed a front splitter on my GSR. it has a 4" front extension that extends all the way to the oil pan. bumper is OEM with mugen lip.

on my drive down to los angeles, i got 38mpg upon fueling. I know i resetted my odometer at the last fill up so this is correct granded all the miles were highway.

the last time i drove all highway for an extended length of time, i only got 32mpg and that was without any airdam or splitter

does this sound right to any of you? 38mpg highway is a lot IMO.

editted: left out some info that i should have included.
average cruising speed: 85mph
mods that matter: 205/50/15 tires, 7.5lb flywheel, cold air intake, 2.25" catback exhaust, 1.25" lowered
fuel at the time: 89octane
motor oil: 5w-30 syn
tranny fluid: synchromesh friction modified
outside temp: 60ish F
terrain: really flat

the splitter is parellel with the ground. i made sure when i installed it, it will not be angled at all.

 

mpg varies all the time, but that is a lot. Keep us posted with an average after several trips. I get that aerodynamics can make a difference but that is still a big difference.

 

I wouldn't have expected that big of gains, but it would increase aerodynamics if it extended to the oil pan it is keeping the air from creating a parachute affect from forming behind the bumper. You could have angled it down in the front, like a little seperation from the bumper, which wouldn't look flush, but it would keep engine temps down as it would force air to the radiator and engine.

 

Streaming doesn't give u 6mpg, how can a diffuser lol?

Lots of factors, driving conditions, tore pressure, etc

 

i m not gonna be driving for extended periods for a while. sorry, but i posted some more info related to this topic in the OP. maybe if i get another interview down south again, i'll make a drive.

 

It could just be that the wind was at your back. I do a lot of interstate driving and depending on conditions I get probably a 6-8 mpg spread. Keep us posted on how your next drive goes!

 

post pics OP.

 

You want him to post pics of his gas mileage? Lol jk I would like to see the splitter installed as well

 

I have the lower part of the 94-97 grill blocked off for winter. When I last drove on the highway with it mounted in September, I averaged 36 MPG. The cooling system is over designed for normal highway driving.