Horrible mileage with Bully dog
 

Hi.

This is my first post. I have a 12 Cummins that I bought, it came with a bully dog GT tuner and the mileage is just terrible. Even unloaded I get 17L/100km (im in canada) towing ive seen it at 24L which is just crazy. Ive tried the different levels extreme works the best but still terrible.

I think I may have to delete it. Does anyone have any recommendations? I read through the guide and it was helpful

I'm in Ontario if anyone knows of anywhere. Or should I order off the web?

Thanks in advance. Glad I found this forum so much good info

Is this warm weather mileage or cold weather? For cold weather with winter blend fuel that sounds about right. If it is warm weather, it sounds a little low.

Hi thanks for the reply. Thats pretty much slightly warmer weather. 13MPG highway unloaded Is horrible I thought. I figured highway with no load it would be closer to 18-20MPG when its decent warm out strictly highway.

This thing is costing me a ton. Ive gotta do something. What will a truck with a delete get driving nicely on the highway?

What is recommended for it. Sorry for the newb questions im just starting to figure out the forum

I can not honestly tell you if you will gain anything by deleting. My truck is all stock. I do get 16 - 18 on the highway empty as long as it is warm out and I don't go over about 70 mph. I can tell you that I tried all kinds of things with my 2005 5.9 to see if I would get better mileage, to no avail. I have documented every gallon of fuel that has been through my 05 and my 15. I tried programmers, exhaust, air intakes and everything I did lost me mileage rather than gained. The biggest reason I know this is all fuel was documented. My belief is it is all snake oil. When you read the info. on a given product their claim is up to a certain amount of mileage gain. That does not mean that you will see any gain at all. By the way what gear ratio do you have? I am wondering if you have 4.10's.

My experience is that you can get 17 to 21 mpg with a deleted 2012. Especially if you're running stock tires.

You're in Canada, so you can still purchase a FloPro exhaust. I recommend the ebay EGR delete and TV delete, should be about $70.

Where are you in Ontario? I am in Michigan, I can help you with EFILive based tuning.

Those numbers are what I was netting with a fully deleted 2012. I used an older Smarty. If I did it again it would be EFIlive.
The newer the truck the less MPG gains from what I’ve experienced. Jmho

If you want good MPG out of a diesel truck get an old one. If you want lots of gadgets get a new one.
I get 20 MPG out of most of my 1st and 2nd gens. Some average 2-3 MPG higher, some 2-3 MPG lower than 20. The earliest '89-'91.0 12V 1st gen get the best MPG for me. the 2nd gen truck get the lower end of the scale, though I did average 22.3MPG hand calculated on my '98 12V 3500 over 1000 miles on my way back from TX two months ago.
This MPG is on 4x4 trucks driven normally usually not even on the highway.

Pretty true with the exception of the DEF trucks. They consistently get good fuel economy according to the reviews and after speaking to some owners.
My '98.5 and my current 2007 get the same fuel economy. 14 with the camper and maybe 19 mpg highway unladen with 35's. I had an Edge EZ and 80 hp sticks on the 24v and EFI on my 2007.
Anarchy guaranteed a cleaner,smoother running truck but not an increase in fuel economy.

My 16 did not see more then 1mpg improvement.
I had to delete it due to the failures of the dpf and egr out of warranty limit. $8K vs 2K deleted and exhaust.
I was very pleased with the emissions intact performance and mileage of the 16.