lnodrog

My previous posting mostly generated comments that I'm already getting about the economy I should expect from my 98 12 valve Cummins - completely unmodified. What I really want to know is, with all the hundreds (thousands?) of options out there (chips, intake manifolds, improved exhaust systems, improved air-intakes, etc.) is there anything that improves mileage above stock levels enough to warrant the cost of obtaining it? It looks like most of the folks in this forum have made modifications to their trucks and I was hoping to find out if any of these are worth the expense. For instance, some simple math indicates that a Banks PowerPack System would require well over 100,000 miles of driving to recoup the cost - even at $2.50 per gallon diesel.

BoostdCTD

There are no power chips for 12 valve trucks. Exhaust system will help gain a little mileage, as will injectors, but the best cluck for the buck is timing. Advancing the timing will make a noticeable change in the mileage and costs nothing but a little work. The banks stuff is cute but a bit overpriced. I don't know if the fuel plate would help mileage but if you stayed off the power it may, anyway you can also do that for free. Look for more info on GunRacer's #100 fuel plate if you're interested.

I'm thinking these are most cost effective to least;
Timing, (fuel plate?), synthetic fluids, air filter, exhaust, injectors

TxDiesel007

I have the powerpack

For a 1996.. Honestly im not too happy with it.. YES its snappy, but alot of factors are left out of it for the price... If i was completely happy with the banks i wouldnt be wanting other mods for my pickup... The list i want goes on and on, but focuses on a 450/1000 goal at the rears... Anyways.. I have my plate back a smidgen for two reasons, stock clutch, and to assist me in staying off of it... which does help my mileage... on my want list is a 100 plate too... Mind you its simply the 10 plate with no top end restriction. I have a banks plate.. i have no clue what its best compared to... i havent pulled it out completely, just adjusted it... Rumors say its close to a six... but i wouldnt know.... Banks is good, but there is better and cheaper out there.. IE a good example the twin ram.. good looks, but according to what i have read.. not much else to it.. Not bashing gale banks though.... he makes some good products i have and run them, and have had no problems with them.... even though i bought the truck already modded.. i have intentions on improving it...

My mileage so to say....

70 MPH at 2000 RPMS (approx) with 285 liberators
in the city about 17-19 mpg
Highway about 21-22 mpg at 2000 RPMS which is about 70

Id say straight pipe ur truck... less restrictions more noise and apparent better mileage.. it worked on my idi 1993 F250.. but it was 1-2 mpg better......

Best advice i can give outta experience is keep it under 2000 rpms, use all gears on ur tranny, and just let the truck work by itself, smooth and easy... thats what i do and it helps.. im in no hurry i just wanna get there.... Be easy on the truck....

Tx

Hemi Cat

Bumping the timing up is the biggest helper for mpg's. Also keep your tires aired up to close to max inflation rating. I keep mine about 5 under max rating. The synthetic oils in drive axles helps some too. And you can't beat good ole maintenence.