Last weekend I pulled my 5th wheel to Lincoln, NE from Brighton, CO. On the way out I had a 100 mile stretch of a pretty good head wind. I'd guess it was around 30 mph. I was full out for that 100 miles. I ran between 20 and 25 lbs. of boost that whole time. I got 7 miles to the gallon going 65mph!

On a good note, I didn't think I could run that sort of power for that amount of time and not overheat. It was about 85* out and I was running the A/C on and off during that stretch as well. It's going to force me to re-think my almost-overheating issues in the summer while pulling the passes in Colorado.

 

Headwinds never help, especially since our trucks have the aerodynamics of a barn door.

My last long drive had headwinds of about the same speed and my mileage went from about 20 to 15.4.

About how warm were you running down the road?

 

yeah the wind is hard on these trucks, I've noticed that big time. I feel like a piece of plywood vertical goin down the road.

Sounds like you need a little better turbo or tighten up the tranny some more.

 

last night on my way home from work i had a 25/30 mph tail wind and i droped
200*egt and 5lb of boost to a normal calm day. i wish it would do that all the time.

 

Not too bad really. I was just a tick over the normal bar on the gauge...whatever that is on our crap-tastic instrumentation.

The barn door gets bigger with the fifth wheel!

Well I've got an HX35W sitting on my bench waiting for a rebuild. That may help some. My transmission is pretty darn tight already. Just rebuilt myself a year and half ago and I have a Hughes TC. Not the best in the world, but worlds better than stock.

 

My EGTs were solid at 1100* with 25 lbs. sustained boost.

 

Those MPGs, EGTs, and boost are identical to what my wife got a couple of weeks ago pulling a 10k lb backhoe and a small dump trailer hooked behind the backhoe trailer with a 35-40 mph headwind at 55 mph in 5th so don't feel too bad about it. And this was on flat terrain, no hills. I sure thought my truck would do better than that. She said she couldn't even put it in 6th or run faster than 55 because the EGTs would climb too high. I wasn't with her so I didn't get a chance to drive it and try it out myself.

 

One thing you can do in the summer months.

If you have a trans temp gauge and engine temp gauge this will apply.

On the right side or passenger side of your engine you have what is suppose to be a trans cooler. In the summer months it turns into a trans heater. All of your engine temps rise and the water going through this cooler heats the trans fluid.

In the winter months it helps warm the trans fluid which is a good thing and helps regulate the temps of your transmission.

One thing you can do to help the stress on your cooling system would be to put a ball valve in the water supply pipe to this cooling unit so that you can prevent hot water going through it in the summer months. Open it in the winter months to let it do its job.

You may want to make sure you have an external trans cooler before doing this so you have good cooling still for your transmission. In my case I have the stock heavy duty cooler located under the bed and its worked just fine in the summer months.

Running 25# of boost for long periods of time in O/D is not the best thing for your transmission even with a good converter. at you speeds however 65mph your moving a lot of air plus the 30mph head wind.

Just a observation.

 

Not much, skip that and get an HX-40