Tune advice

[SsgtMark]

Bought a 16 Laramie Longhorn. Deleted, 5 inch exhaust, S&B intake, leveled, 35 x 10.5 tires. EFI live set to level 1. People always asked how great is the mileage. I think it is horrible. Usually the lie-O-meter says 19. On a 2000 mile trip with a 8000 lb camper I got around 11. Do I need to change my tune. With this mileage I may go back to a gas. Same crappy mileage and cheaper fill up's. Explain this tune stuff someone please! The vendor that sold the tuner to the previous owner won't give me any info. Is it safe to tow on level 2? Are the 35's the issue, or leveling kit, which I despise?

 

[Fast69Mopar]

Bought a 16 Laramie Longhorn. Deleted, 5 inch exhaust, S&B intake, leveled, 35 x 10.5 tires. EFI live set to level 1. People always asked how great is the mileage. I think it is horrible. Usually the lie-O-meter says 19. On a 2000 mile trip with a 8000 lb camper I got around 11. Do I need to change my tune. With this mileage I may go back to a gas. Same crappy mileage and cheaper fill up's. Explain this tune stuff someone please! The vendor that sold the tuner to the previous owner won't give me any info. Is it safe to tow on level 2? Are the 35's the issue, or leveling kit, which I despise?

The 35" tires are definitely a hinderance in fuel economy as well as the leveling kit. The higher the truck is off of the ground the worse the airflow under the truck. You can tow with the tune turned up at level two if you want. You can tow with it on every level if you want but you need to know what is happening. Tuners add fuel. Fuel creates heat. If you have an EGT gauge then you can watch the gauge to keep the EGT's down while still making power.

11mpg is not terrible while towing an 8,000lb brick wall. The one thing that is probably hurting your economy is your speed. Do a test with your speed as the only different factors. Drive a tank of fuel like you normally do. Then drive a tank of fuel where your top speed is only 57mph. Record the difference. You will see there is quite a bit of difference between the speed limit on the interstate and 57mph.

 

[Dennis Shellito]

If you bought a diesel because you want better fuel mileage while towing, you thought wrong. The advantage in towing with a turbo diesel is pulling power not necessarily fuel mileage. The 35" tires aren't doing you any favors for mileage unless someone installed 4.10 ratio gears under it. Is your speedo accurate? I would advise you to hand calculate the fuel mileage based off of actual miles driven to see what it is really making.

 

[SsgtMark]

I have a friend who says with a 6 inch lift and 37's he gets 19 towing a 14000 lb trailer. The question is do I undo some of the things I don't like or just sell. I would go back to a 4 inch exhaust, stock tires and no leveling kit.

 

[SsgtMark]

Fuel mileage did move up 2 mpg going from 69 to below 65.

 

[SsgtMark]

Can the 685RE transmission handle setting my tuner to the 90 hp setting for towing instead of the 30 hp setting? And will that help?

 

[Fast69Mopar]

I have a friend who says with a 6 inch lift and 37's he gets 19 towing a 14000 lb trailer. The question is do I undo some of the things I don't like or just sell. I would go back to a 4 inch exhaust, stock tires and no leveling kit.

I have a friend who says with a 6 inch lift and 37's he gets 19 towing a 14000 lb trailer. The question is do I undo some of the things I don't like or just sell. I would go back to a 4 inch exhaust, stock tires and no leveling kit.

I would take your friend "MPG's" with a grain of salt. His EVIC may show that he is getting 19mpg but that is no where near what the calculation will be on paper. My guess is he would be around 11.0 on flat ground without a headwind.

Also, you can tow with your tune turned up but you have to pay attention to the heat that is created. Pay attention to your engine temps, oil temp and trans temp. If you can see EGT's then watch that too. The 68RFE can handle more power but you have to be smart with it. If you want to be able to go harder on the throttle while pulling uphill and not having to let off then no, it will only put up with that style of driving for a short period.

If you let the motor and turbo work and keep the trans in the right gear while pulling then you will be okay as long as everything is in proper working order and the truck maintenance is taken care of.

These are my opinions. Please do your research and make the best decision for yourself and for what suits your needs.

 

[Gr8bawana]

I have a friend who says with a 6 inch lift and 37's he gets 19 towing a 14000 lb trailer. The question is do I undo some of the things I don't like or just sell. I would go back to a 4 inch exhaust, stock tires and no leveling kit.