I'm getting ready to buy a Yakima Mega Warrior roof rack and plan on mounting my 245/75/16 on top as well. I'm a little concerned about how this is going to affect my gas mileage. This is my DD, and I just finished upgrading the injectors and tweaking the engine to vastly improve my MPGs. I don't want all of my work to be for not. I'm taking a lot road trips this summer and with $3 + gas I want to make sure I'm maximizing my fuel efficiency. The mega warrior does come with an air dam that should help with aerodynamics some what. Does anyone out there have experience with this? Are my MPG's going to plummet if I throw a spare tire on the rack?

 

I don't think they're going to plummet on the order of, say...towing a trailer. You may notice a slight difference, but I doubt it's going to make you bankrupt.

 

I added a sporttrac rack with a air deflector and did not see a change to my fuel mileage.

 

Do you have a roof mounted spare as well?

 

i wouldnt know if it'll effect your mpg. what i do know though is a buddy mounted a spare up there and hated it because it was heavy and a PITA to put up there and get down. lol

 

My son in law put his up there and it made lots of noise when wheeling and going down the highway so he took it off but I don't think it effected the mileage...Tj

 

HAHA no but 99.99% of people on here have it. The roof rack with a tire. Kinda made me not want one, it looks good and doesnt really hurt your mpg's. You should not have to worruy with it

 

I had an empty Yakima rack on mine - when I took it off, I could swear I was getting an extra 2 MPG or so on the highway. No difference in the city, as you could assume.

There were no other changes to the Jeep, but you could blame the difference on differing wind conditions and such.

Run it, and see what happens. Probably the worst that will happen will be a few MPG's, and you could take it back off if that is too much to justify having it. Just attach it well.

 

if you have money to spend on a roof rack and a full size spare i dont think a couple mpgs will make a diff in your pocket.it looks badass thats really all that matters

 

I have a 30" tire on my roof with the Mopar spare tire mount (no basket. no air dam). It has been up there for almost nine years and I think it may cost me 1 mpg but, not a whole lot. When we drove to Camp Jeep back in '07 (Ohio to Virginia) I averaged a little over 20 mpg at 65-70 mph.

 

What he said