I've got a 98 2500 v10, and I have been averaging about 9 mpg. My truck doesn't have an air dam up front, and I run oversize Micky Thompsons (I know, that doesn't help at all) for tires. I was wondering if it would benefit my gas mileage to put an air dam up front, or if there are any other mods that help as well, without being too overboard.
thanks

 

Air dam won't make any difference at all. It's that big hole in the gas tank, that leads directly to 8 liters of VERY thirsty V-10 that's the problem. 9 is actually about average for these trucks. You might eek a bit more out, by doing a fresh tune-up, and changing the O2 sensors. (NTK or Denso only please, skip bosch, our trucks don't like 'em.)

Dropping back to stock tire size would help, or, as an alternative, regearing for the tires. Aside from that, just not much you can do. It IS 488 cubic inches after all.

And yes, I am in the same boat.

 

The o2 sensors may or may not be gone, so would it be worth it to put them back in even without cats? It definitely runs rich, it smells like you could hold a lighter down at the pipe and get a flame.

 

Yes. Definitely worth having them. Dodge runs them fairly rich by default, O2 sensors compensate for that. One of THE best things you can do for gas mileage. (I won't even consider calling it 'fuel economy' on these trucks..... they are anything BUT economical. )

 

So, I looked below the truck tonight, and found that both banks do indeed have 1 sensor still hooked up. Is there supposed to be another after sensor 1 that would be beneficial to replace? I should mention that I am running performance headers as well.

 

8.0 has one sensor for each bank. There aren't any post-cat sensors, so, need to replace both of them.