What chip should I get for a 1999 PSD ?? I tow but not everyday..mostly highway everyday

A friend has a two stage chip that is switchable from the drivers seat. One mode is for towing and the other is the "Go like hell mode" . It works really well. If you want I can try to find out exactly where he bought it.
He also has the five inch exhaust system on it.

Diablo is the one I have just about doubled my fuel mileage

I heard western diesel makes a really good chip with 4 hp settings but i've never tried one. Whatever you buy i'd recommend buying a set of pyrometers also.

Turbo or not?

http://shop.ivalueinternet.com/Micro...oduct_id/1.htm

I have had real good luck with the Superchips Micro tuner. Has two HP settings plus the new one is also a code reader, which is a good thing to have.

I had an ATS (Advanced Turbo Systems) 3 stage. I was very happy with it.

diablo works great.. i have the switchable awsome

I don't know why I didn't mention this. I just bought a 115 hp chip for my 6.0 Powerstroke. Ask for Doug.

Also a friend with a 7.3 just bought a chip from them too. He is very happy. Alot of smoke though. He then bought a bigger turbo and cleared up most of the smoke and really did alot for power. His only problem now is he needs a new trans!!!

Oooops, forgot the link

http://www.smokindiesel.com/index.html