Can I improve my gas mileage?

mkirsch wrote:
Check your universal joints.

I was losing a good 1MPG because the u-joints were seized. Didn't notice until late last year when the truck started making a "sqicky-squicky" noise as I was backing it into the barn for the winter.

Pulled the driveshaft over the winter, had new u-joints installed. Mileage this year is about 1MPG better.

That is a really interesting idea - I've got a slight squeak that I think is a U-joint going. Plus I noticed my gas mileage isn't as good as a couple of years ago - maybe I should do something about that UJ.

Steve.

Two words. Slow down.

You are doing pretty good considering the increases you have from towing. You can make the vehicle more aerodynamic. An air dam up front to divert the wind away from the under carriage will help.
Also, most engines run too rich. You can research how to spoof your MAF, O2 sensor, or MAP to trick the commuter into running a leaner mix. This absolutely worked for me. The danger is that if you lean it out too much then the exhaust temps get too high and burn your valves up. Ideally you should monitor the exhaust temps when doing this.
I have a truck that is rated at 17mpg highway and I get 22-24.
I have not done this to my RV since that engine is known for running hot and blowing exhaust gaskets anyway.
Do not buy that "chip" on page one somebody suggested, it will work, but you can go to Radio Shack and buy a potentiometer and do the same thing manually. All the "chip" does is cut the signal voltage, which does spoof the computer and does work, but it is a 25 cents chip.

My last two trucks have been a diesel, but I don't agree that they are needed for everyone or cost effective. In my area, I have mountains to cross regularly and decided to pay the premium to be able to cross them easier and for future planning if I go with a fiver later. The diesel with 4.30s does that much easier. Mods can make a gasoline a lot better and I was close to getting one if I wasn't thinking about a fiver.

I have done a variety of modifications in the past. The most extreme in cost was when I put a Banks Power Pack on the Class A that I had which both increased the mileage and also made it possible to go up the passes at the speed limit with minimal shifting pulling a Jeep. I made the change after struggling up the Vantage hill. Those of us who drive the mountains have seen lots of RVs beside the road with transmissions dead. I didn't want that to be me with my family. That was years ago.

I had a '97 Ford Expedition that had two catalytic converters when one was failing. I replaced the whole exhaust with two high performing catalytic converters and more flowing mufflers all at once for slightly more than what one OEM catalytic converter was going to be. The end result was about 2 MPG improvement in town and a shocking amount of increased power and that was without a tuner. I have a tuner and other basic mods on my Mustang which completely woke it up. I have a rather basic SCT tuner on my Explorer that improved the mileage and kept it from shifting at strange times on slight grades.

There really is a lot to do if you want and even minimal changes can help gasoline engines get better mpg, more air is good. Still, no doubt that the diesel is nice for what I do with mine.

Only way to improve mileage significantly with that setup is dump the truck for a diesel. IMO.
Don't be fooled into thinking any newer gasser is going to get significantly better mileage with that load either.
My old '13 F250 gasser knocked down a whopping 8-8.5mpg avg with about 1000lbs in the bed and a 3000lb single axle enclosed sled trailer. A lot of the driving was slow(er) too beings it was mud season on the Alcan hwy and the frost heaves were at their peak!

Check your universal joints.

I was losing a good 1MPG because the u-joints were seized. Didn't notice until late last year when the truck started making a "sqicky-squicky" noise as I was backing it into the barn for the winter.

Pulled the driveshaft over the winter, had new u-joints installed. Mileage this year is about 1MPG better.

I had a 2004 GMC 2500HD, 6.0 liter, gas with an 8' utility bed on it and all I could ever get out of it was 10 MPG not towing anything. Towing a 5' x 12' utility trailer, it was around 7.5 - 8.
Currently our 2008 F-450 6.4 L diesel and towing our 43' Cyclone Toy Hauler, the best we did was 6.5 on a long trip from California to Nebraska and back. So, even the diesels are not that good mileage wise.

You 'tracked' the mileage at 7 mph
You 'think' you use to get 9-10 mph
This trip you towed the Jeep

In past when you think you got better mileage was that also when towing the Jeep?

Gas mileage is flighty ......so many variables change/affect it.

Hot/cold weather temps, wind/no wind, grades/flat, speed, refueling techniques, acceleration, braking etc.

I get 10.5 -- 11.5 towing FW
Have only gotten 5 and nothing was wrong.........just headwind

Unless you are using tow hubs flat towing that Jeep is not only extra weight you still have the resistance of turning the gears in your differential possibly front and rear plus transfer case and transmission depending on how your set up.

jimh425 wrote:

trail-explorer wrote:
Educated Jeep guys never run K&N air filters because they allow dust to pass through.

OPs not talking about a Jeep driving in dirt or a Turbo diesel either. :) If he had, I wouldn't be suggesting a K&N.

Regardless of what kind of engine or the conditions it's driven in, I still can't recommend a K&N due to the holes I've seen in the filter media of all the ones I've looked at new out of the package.