sup guys,


I think theres a leak in my gas tank...my truck is registering 8.5mpg on the overhead computer . Although I just added tsl tires but I feel like it shouldnt be this bad. with BFG AT's I was getting 13. So the question is...will giving my truck a proper (SCT) tune help find some more power and increase in milage in my HO 4.7? theres gotta be untapped potential in these motors. I got mild bolt ons...K&N, throttle body spacer, (noise maker) and a Flowmaster 50. I might get a custom Y-pipe built with hi-flow cats...but thats to much money for right now. Or maybe a Y-pipe with out cats? make it able to be bolt on and off when it comes time to smog. and cheaper... what do u guys think??

 

Holy knobby tires!

8.5? That's ridunkulous. I get 12-13 now and wanted to get aggressive treads but I'm gonna rethink that now. :/

 

i am going to guess your tires may actually be the culprit.

 

With my SC 3865, it did not help out with mileage at all. It always sucked!

 

How much did you increase the size of your tires? Have you tried hand calcing the MPGs? The computer is only as accurate as you make it, if that makes sense.

I wouldn't necessarily say a tune is going to give you better fuel mileage. Its not really a fix all and as everyone knows, you can;t build horsepower without fuel. It, however, does improve the drive-ability. I would say overall (the past 2 yrs), I haven't gained nor lost mileage and that's running my Superchips canned tunes, again I have noticed better drive-ability, firming, more responsive shifting, and power throughout the rpms. I do get better mileage in some areas of driving and worst in others, so it all averages out.

Btw I do like the aggressive look of your setup...

 

Thanks man!

and everyone else for responding...My tires didnt increase in size that much. stock bfg's 265/70/16 i think? I went to a 31x12.50x16. but the dealer told me that super swampers run big...so maybe they're 32's. I feel like i didnt include enough detail in my mpg rating. Its only mesuring a very short distance, from my house to work which is about 2 miles give or take...but it includes going down a huge hill then coming back up it. it doesnt have any highway in the 8.5 mpg rating. maybe thats why? very crappy rating in town thats for sure! Im gonna fill the tank up and just see what milage I get per-tank. (distance in miles divided by how many gallons you fill up with) I also have done another tasteful mod you guys are gonna like. I have the run-cool hood louvers on my hood...ill post a pic as soon as I can.

 

Those tires are killer! IMO, a tuner will not help at all with mileage because your always like, "whoa, I didn't know I had this much power, this thing is a blast to drive!" and your always on it...(at least I am...lol). Even when I tried the mileage tune with superchips, I did not see any real gain in MPG. I get a steady 16.5 mpg around town/driving to work (40 mile round trip) and maybe 18 on a highway trip if I keep the cruise on at 65 the whole way. 8.5 really sucks. I have not had that bad since high school when I had my 75 Camaro Z28 with an LT1 350 and a Muncie M-22 rock crusher 4 speed. Man I miss that car sometimes....

 

yup, exactly what he said ^^^^ cant keep your foot out of it.

 

Here are your 2 biggest problems that are killing your gas mileage. First- your only driving 2 miles to work. The engine never gets up to full operating tempature so your always running rich. And 2nd, Super Swampers TSL or anything they make are heavy tires so the extra wieght doesnt help. Also, a TB spacer is nothing but a useless paperwieght on anything but a carburated engine.

 

He did say the TBS was just on for making noise. . . .