I just recently installed a Magnaflow catback and S&B intake to my 08 4.6L reg cab truck. I have a 26 gallon tank and prior to these mods I got right at 300 miles per tank. That’s about 11.53MPG.

The day I installed my intake I put 50.00 (12.56 Gal @ 3.98 per gallon) worth of gas in my truck, exactly half a tank according to my gauge. I am now at 200 miles on this 1/2 tank and I still am not on empty. Now, 200 miles on 12.56 gallons means I am at 15.92MPG and I still have gas left, about 1/8 of a tank so the milage is still getting better. Incase your wondering, I do not drive slow. I usually am at WOT a few times while on the road. Passing people and such. I love the new found power and sound of the exhaust so I hit the gas to play.

I have noticed that my truck cruises at 65MPH at about 1800 RPM's and 70MPH at just under 2000 RPM's. This is lower than it used to be by a couple hundred RPM's.

To me, this is a huge gain. I have picked up roughly another 100 miles from a take of gas. Is this normal improvement for an exhaust and intake?

 

good to know. i'm picking up my S&B intake today, already have a magna-flow with straight pipes. hope it helps my mpg. power is good, but i'm right at 12.6 every time.

 

damn man. i only fill up half a tank at a time and routinely get 200-220ish. my commute is almost all highway though.

btw, if you're cruising, rpms are a function of engine speed and gearing. an intake and exhaust aren't going to change your crusing rpms. my truck cruises at about the rpms you posted.

 

It could be that I never really paid attention ot the RPMS before. I could be mistaken on that count. I drive fast and rather agressive. I have 36 moving vioaltions on my record and no less than 6 points at any given time. I am not a miser behind the wheel and my truck is more for my enjoyment than a work vehicle so I can afford to play with it rather than shoot for good milage.

Now, if my wife ever leaves me and takes her Escape that gets good MPG, I am srcrewed. lol.

 

Do you any of you guys think that an intake helps with fuel mileage, enough to make it worth the money??

 

the most accurate way to tell ur mpg with diy calculations is to fill it up all the way, set your trip then drive til you need gas and fill it up again. divide the miles on your trip by the gallons used and that is what you are getting. i say this bc just by looking at the gauge and see it appears to be 1/8 tank could be slightly decieving and make a difference on what youre actually getting in mpg. i would try that a few times and see if you get the same results

 

I went by the number of gallons vs mile achieved. I never use the guage to figure mileage. I was just bringing up the 1/8 tank to show that I still had gas left. No way to tell how much exactly. I am going to fill it up completly and set the trip to see how many miles I get out of a full tank. I do know that the two times I have done that so far I have gotten 283 on one tank and 307 on the next. If I can get 400-450 I will be happy.

 

sounds like a plan. let us know what you get then

 

you cant rely on gas gauges in these trucks to calculate fuel mileage. you have to fill it all the way and do the calculations.

 

Lots of debate on this topic. Some say yay, some say nay. You truck should compensate for the extra air by adding more fuel (air:fuel ratio) which wouldn't equal more mpg's, but more "efficiency" as in more HP, torque for the amount of fuel used. I could be off on my calculations, but it's what I've heard that makes the most sense.

I can tell you for sure that if you're buying a CAI just for MPG's it's going to take a LONG time to pay for itself.

 

Yay! 215 miles on 12.56 gallons. 17.11MPG. My little dinging gas reminder just came on too. Any idea how many miles I have left whe it says LOW FUEL? I am getting gas tomorrow so its not a big deal. I am just curious how many miles the dinger says you have left.

 

It's not good on your fuel pump to let your gas continually get that low. However, in a pinch between gas stations, I made it 3 dings, and 24 miles. Wouldn't push it that far again! I usually fill up with 1/4 tank left.

 

first time and hopefully the only time it will get this low. Cool. So it is close to meaning my **** is footing it! LOL

 

I noticed that after installing the CAI my rpms were lower also at cruising speeds. I got flamed saying that a CAI would not lower the rpms that I must have hit the over drive button. It's good to see I'm not the only one that noticed that.

 

Thats great results, glad to hear everything came together for ya