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Looking to buy a programmer for my 2001 GMC sierra 2500 hd. I don’t have much background knowledge on them and was wondering what would be a good buy, Looking to increase fuel mileage as well as towing power.

You have to look at the cost of the programmer and then figure out how long it will take to recoup the cost of the programmer before you’ll see a benefit.

If you you want to increase fuel mileage you can’t have towing power and vice versa.

All these programmers do is take the mapping of the computer programming and push it out of it’s normal operating range. So depending on where the programmer is set, depends on how much wear is put on the engine/transmission.


I’ve heard Bully Dog is easy to install and use an provides good customer service. However, be aware that you are modifying the fuel mapping of the ECU, and errors in that remapping can cause expensive engine damage.

If you’re willing to exceed emissions, then you should be able to improve both fuel mileage and power. As BustedKnuckles noted, be careful, as you can cause engine damage.

“Looking to increase fuel mileage as well as towing power.”

Good luck with that. That’s like wanting to increase your bank account without making a deposit. I would forget the programmer and start shopping for another vehicle to meet your needs or maybe a supercharger for your current truck.

You shouldn’t do this, period. A couple of years ago we had a discussion from somebody who bought a programmer for their Ford diesel from the best-known brand in the business, and proceeded to ruin their engine. They voided the Ford warranty so the cost to replace the engine (over $10,000 I think) was 100% on them. You will read lots of claims by sellers and buyers, most of which are made up. You will NOT read about the folks who wasted their money, or, worse, damaged their engines. Few people want to admit to those kinds of screw-ups.