What kind of RPM's do you get? What about MPG?

crasster wrote:
Just curious what others out there are getting as I look at TT options.

I've heard that 2400RPM and 7.5MPG is pretty standard. Is it wrong?

2200 RPM with my truck, and trailer will get me 10 MPG.

We cruise at 70 mph and RPM's run at 1700. Depending on terrain and wind we get between 7-14 mpg towing a 10,500 lb 5th wheel with a 2018 GMC Duramax diesel.

There is nothing standard about towing at all.
I have an old Ford diesel and pull a Rockwood around 5,500 pounds.
The diesel likes 1900-2,200 rpms, and gets around 12-13 mpg, pulling a boat around 16-17, empty over 20 mpg. My record is 23.8 mpg.

It is the last of the 7.3 diesels and 444 cubic inches.

I tow a 2017 KZ Coachmen Classic 181bh with a 2006 Kia Sedona EX. I drove it from Dallas to Port Aransas on 1 tank of gas. My rpm is usually around 1900 - 2700. In the hill country, it can get up to 3000 rpms but drops back down after climbing.

My gas mileage is around 19-20 mpg. Going back to Dallas, my gas mileage dropped to 15-17 mpg. This was due to going uphill and a strong headwind.

I am amazed at the gas mileage I get with this Kia. It tows like a champ and I hardly know the trailer is back there. In Europe, the same Kia is rated to tow 4500 lbs instead of the 3500 rating over here. Even though my trailer only weighs 2700 dry weight, I believe my Kia could easily handle a lot more.

We tow a 38' toyhauler that weighs around 18k with a Dodge dually that is outfitted with a tow package. 4.10 gears. We always run at 60 mph. We run at 1800 rpm and get about 11 mpg.

To many variables must be the same, or very close together for a rule of thumb you list to work or apply

Example is the HP required to overcome all of the losses...then what HP is required to do the job of moving and keeping at speed for your setup


That HP min should be at the min RPM found on the torque/HP curve graph...therefore throttle setting. Note all of these graphs is at WOT

Losses...pumping, frictional, drag, sail area, inertia of mass, rolling, etc, etc and note that they all increase as the speed increases

Too many factors involved to make a blanket statement. When I had my Trailblazer and a 3500# GVWR hybrid, I got 11 pretty regularly at 2600 RPM in 3rd gear. When I started towing the X20E (4750# GVWR) in my sig with the same Trailblazer I got 8-9. When I got the Sierra I get 10 mpg regularly at 2400 RPM towing the same X20E.

In other words different combos will give different results. I've never been concerned about either RPMs or mileage. RVing is not cheap. I only monitor mileage because diminished mileage over time can indicate potential issues. But generally speaking you can figure somewhere between 8-12 mpg depending on the combo.

A 5w will almost ALWAYS get better MPGs than a tow behind per some past posters that delivered trailers. Best was a non slide smooth walk 5w. Worst, an aluminum corrugated sidewall TT. Aerostreans also did fairly well too.
So if trailer choice is heavier by 400-800 lbs of smooth walk siding, the better wind resistance aerodynamics, more than makes up for heavier trailer!
With this also said. At least diesels, and older style gas motors, on level towing etc, best mph is at peak or just below peak torque. 1600-1800 rpm or so.
Best pulling power on a grade, is looking at an HP torque chart, pull at RPM share those two lines cross. Generally speaking, half way between peak torque rpm, and peak HP RPM. Example, peak torque is 1800, HP 4000, best hill pulling on a long grade is to hold around 2900-3000 rpm or there about.

Marty

Weight and profile of the proposed TT? Weight in the TV?

Gas or diesel?

My 2012 F350 6.7 diesel towing my high profile 34’ 5er typically gets 10+ mpg at about 1,800 rpm. High winds or mountains knocks the mpg down quite a bit. I would expect towing a typical TT it would do a little better.