Diablo tune+ towing = horrible mpg

I have a 2011 ram 1500 quad, and just put a Diablo 87 tune in for towing my sled trailer out West and I'm getting a solid 2mpg worse with it? Is that normal? Trailer sleds and gear cant be more than 4k lbs, and with a 20 mph head wind I was getting 7mpg!?! Went back to stock and instantly up to 9mpg, still not good but ya...

So what you guys think?

Hmmm... Did you have more uphill with the tune? Did the headwind die down? Bad gas before a refill?

B-g-K said:

Hmmm... Did you have more uphill with the tune? Did the headwind die down? Bad gas before a refill?

Click to expand...

Two tanks in a row it was way low? Still not good at 9 though. Truck only has 16k mi on it so I wouldn't think its an exhaust issue? My volant intake filter maybe has 10k on it so that should have plenty of life left? Ibe got nothing lol.

DAAAA-YUM!
Subscribing to this as I'm on the fence about a tuner, and we bought the truck to tow.

I have seen that kind of drop in a stock truck. Although towing my travel trailer I am in the ~12mpg range and it is 2x the weight you are towing. Hum...

Try the 93 tune.

Thats just it, its a low trailer only a foot or so taller than truck. Idk?

My old man has an identical setup and truck and with the 91 tune it wasn't shifting worth a crap? I can try it though?

are you using tow/haul mod also? If you aren't you could be slipping the trans and could be causing loss in mpg.

Could using 87oct be part of the problem?
I asked Sean (Hemifever) about towing and he said his 89 tune would work fine for towing; if 87 is acceptable but 89 is suggested for daily driving, imagine what could be going on inside your engine when it's working hard while towing?
Just offering some thoughts on what it could be.

^^^^ This is a very very good point.

The manual says the engine is designed to operate on 89 octane. Can't imagine why you'd get worse milage running 87.

Fill that sucker up with 93 or 94 and use the 93 tune. Forget about the 87 tune, its not worth your time!

To the guy that cant imagine why:
Imagine octane rating as how hard it is to ignite the gas. Higher the number harder it is. Now to attain the highest efficiency the motor must be working to its maximum capacity. If it is running on 87 (or 89 compared to 93 or 94) the air fuel mixture is igniting before the piston is fully at the top of the cylinder. This causes a knock because the piston is still coming up but the flamefront is moving down. The computer sees this and pulls timing accordingly.

Now you can imagine this happening while you are rolling down the road, now put a trailer behind you and demand more from your motor, i dunno about you but i know what kind of gas id run if i had a tuner (or a trailer)
Hell i dont even have a tuner and i run 91! Quality over quantity for me!