I realize I'm setting myself up for some potential grief here, but has anyone experienced any mileage gains from installing grill inserts / stone guard / doing the 'grill mod'?

I install a fairly tight-pattern expanded aluminum sheet behind my grill over the weekend. I swear the jeep is a little less of a hassle on the highway now. I also managed to click off an indicated 24-point-something MPG on my 30 mile highway commute home. That's a new high.

If its not the grill, I'm guessing my area gas stations switched fuel to the summer brew..

 

Jeeps are like a barn going down the hyw so I doubt the grill changed anything but I bet your right about summer fuel it has a faster burn and less bs in it.

 

I hear you on the barn door thing. I used to be into modding street-trucks.. I knew of a few guys who'd block off their grills with plexi-glass and pull their mirrors in to gain a few mph in the quarter. I'm not sure if any of them ran consistent enough times to say whether or not it worked, but the claimed it did. After my little grill mod, I had to wonder if they were right.

I agree on the gas thing though.. its a definite switch in my area. Always hate it when they go to the winter mix. Its like you're dragging an anchor.

 

Nascar uses grill tape for the same reason, but this on a car built with aerodynamics in mind, and at nearly 200 mph.

Gonna go out on a limb here and say it has no real effect, other than blocking cool air to the radiator if the grill is actually fully obstructed.

 

I know a Nascar is a totally different beast but tape over the grill affects them by a lot. The Jeep is so blocky that I can't see a ton of improvement but who knows!? Wind tunnel test her!

Edit: you beat me to it.

 

uhm I think not