Well he said he gets 240 and his light comes on..which is around reserve level. 5 gallons.

so simple math states: 12mpg city.

Same thing with highway.. 20 gallons gets him 345. That's 17 mpg.

I get about 480 miles on a full tank (about 22 gallons or so) which comes out to 22 mpg on the highway. But this is with the 5 speed auto.. I thought I read somewhere he had an 03.

 

I have no idea how far I'd get before the light comes on because I never let it get that low. I get between 12-14 average and 16-19 highway.

 

I had no idea how big the "reserve" was. Thanks!

 

I get 11 city and 13-14 hwy on my 5.9. Was thinking of changing out the cat with a higher flow cat and free flow exhaust to see if I can up the mpg even by 1 would be nice.

 

holy **** that sucks.. 14 hwy?

Even if you got just 1mpg.. it’d take you FOREVER to regain that money back by getting a higher flow cat and exhaust..

 

What are your driving habits like? Heavy foot, grandma driver? Did that F1 intake do anything for mileage or power? I have seen people claim up to 6 mpg gain with it, maybe it was even the manufacturer claim. I don't believe it for a second, but a modest gain wouldn't be out of the question.

 

I get the same mileage on my 5.9 Kensai.

 

I got a 5.9 and a heavy foot and get the same.

 

Depending on where and how I drive my 5.9 1999 with 4spd auto tranny and 4x4, I get an average of 11mpg driving city, and 15-19 hwy depending on speed and conditions driving normally without a heavy foot. I was at 13-16 hwy before I put on my Flowmaster 40, new air filter, and new premium sparks. My city stayed the same, but my highway mileage is what makes a difference. I can get 20mpg driving like a granny doing optimum at 55-60mph and coasting to stop lights and such, but it's hard to when I know I can wind I out and make it sound good. I don't get any drone, and at cruising speed, I can't even tell it's there.