towing mileage of trucks

I'm going to put my 2 cents in here. On my Dodge, I put 19.5s on it and had a slight gain in fuel economy when driving down the highway and towing. I had a slight drop in economy around town, they are heavy, but have less rolling resistance. There are a lot of factors that go into economy and engine efficiency is a big part. Blanket statements will surely get you into trouble.....Just my experience.

Moved from General RVing

Cummins12V98 wrote:
I stand by my statement, more weight equals less fuel economy.

I also stand by my statement that a 17/18 F350 will pull any DRV out there just fine like my 15 RAM will within axle and combined ratings. So why spend the extra $$$ on a 450??? OH yea for the tighter turning radius?

Heavier running gear, larger brakes, 19.5" tires. The optional V10 on Ford's or Aisin trans on Rams.

Automotive diesels achieve 40-45% thermal efficiency, the biggest ship diesels are 51%, if you think that a few bolt-ons can achieve 80-90% efficiency and the really smart engineers at all the world's auto companies are spending tens of billions to eek out a few more percent then go ahead and hand over your $2,000.

2Macs wrote:
Okay, for you guys who think my mechanic is full of it. Would you experts recommend spending about $2,000 for the lift pump and tuner for increased MPG of at least 15 MPG+. Other ideas?

Okay, EFI live is a good system for additional power and may net you slight mileage increases. I’m talking 1-2 mpg in the right situation. You’re not going to get any magical significant milage gains over stock without hyper miling and accounting for every little inefficiency. Period.
Your truck does not have a lift pump in an OE configuration. Doesn’t need one, but some think it may extend the life of the inj pump and a lift pump is only needed in big HP applications on a Dmax. I could run 150hp+ tunes and not starve the CP3 on my old LB7 with no lift pump. It does ZERO for fuel mileage.

Not being rude, just didn’t not want to see you get hosed here, I don’t think, I am certain your mechanic is one of 2 things.
1. Trying to generate business. Won’t say rip off because they’re valid mods and labor is labor. Idk if 2k is he right number. Parts are $1000 plus and labor is 3-4 hours total.
2. He’s just a diesel junky goofball who actually believes some of the hype and thinks everyone should have an Airdog and EFI!

2Macs wrote:
Okay, for you guys who think my mechanic is full of it. Would you experts recommend spending about $2,000 for the lift pump and tuner for increased MPG of at least 15 MPG+. Other ideas?

NO, you will never get 15mpg!!!

Okay, for you guys who think my mechanic is full of it. Would you experts recommend spending about $2,000 for the lift pump and tuner for increased MPG of at least 15 MPG+. Other ideas?

Grit dog wrote:
Who drives 50mph?

Your secondary highways are not 50 mph speed limits?

In Ontario we have over 10,000 miles of highway but only about 15% of them are 60 mph highways, the equivalent of Interstates.

"Lift pump, better filtration and tuning are real things that have benefits, just not what he says. "

VERY TRUE!!!

JaxDad wrote:

Cummins12V98 wrote:
I stand by my statement, more weight equals less fuel economy.

I also stand by my statement that a 17/18 F350 will pull any DRV out there just fine like my 15 RAM will within axle and combined ratings. So why spend the extra $$$ on a 450??? OH yea for the tighter turning radius?

I’m sorry Sir, but your statement is simply false.

I have an F350 and an F550, under similar loads at 50 mph, 80 kmh, my F550 gets better mileage. Both of them (combined weight) outweigh my Class A motorhome and get better mileage than it does.

More weight does NOT equal LESS mpg.

More EFFICIENCY equals less mpg.

Lol, well more efficiency should equal MORE mpg, but maybe it’s opposite in metric.
Also make sure you’re talking apples to apples about your mileage claims, they’re suspect. But at 50mph they should both be getting decent mileage for what they are.

Who drives 50mph?