1999 cummins better mpg?
 

hi

I have a 99 cummins, all I have done to it is, quadzilla adrenalin, ats auto tranny, fass fuel, 34 inch toyo at2's. what can I do to get better fuel millage?? im getting 14 mpg going to work and back. don't don't pull anything hardly ever.. could you help me out?? :w2:

What gears, is that a dually, 4x4, what kinda mileage were you getting before the mods?

im not sure about the gears but its a 3/4 ton, 4x4, and I think the same milage but I didn't put the ats in, I bought it with it..?

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im starting to think it is the ats tranny that is sucking down my millage!!?:argh:

I believe there is a sticker in your glovebox that tells you what the gears are. There is in mine at least.

would the gears really matter for everyday driving??

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it says alex ratio is 3.55 and dayna 60 front?

Oh yea it does. My dads truck has 4:10 gears and mine has 3:55. Makes a big difference.

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My dad is lucky to get 18 on the highway. I can cruise at 65 mph and get about 23 all day long.

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But they are both manual trans.

Are your truck and your dads the same truck and everything do to it the same other then the gears?? And I have 3.55 gears and I'm getting 14mpg???

For the most part. Mine is built more then my dads is. I think his needs injectors also which could help. But he's to stubborn and cheap to do it. Mine is a couple years newer and is about to hit 200k. Do you have a bigger intake and exhaust on your truck? Making the engine breathe better will help.

you're getting 14mpg because of your lead foot and over sized tires.

set your quadzilla to PL1 and go EASY on the throttle there turbo :tu:

try to keep your egt's below 600* and boost below 5-10psi...

also make sure you have a clean fuel filter, clean air filter and don't drive in lockup mode.


to further add insult to injury...

I'm getting 15.5MPG with oversized mud tires, and HUGE injectors that cause the truck to haze at idle with compound twins to back them up... If I can pull off 15.5 with crap gears (4.10) a manual trans (NV5600) and a live in an area riddled with hills, then you can pull off much better mpg's by changing the way you drive a bit :tu:

or maybe just slow down if you are one of those that cruises 80mph...(lead foot!)

Yes I have the truck straight piped, 4". And I have a k an n cold air. And haha I don't drive it like a bad out of hell! Hahaha I think it has to do with the ats tranny. I drive totally different then my buddy's with a auto stock tranny.???