big rig mileage with RV weight trailer

[EricBu12]

Today I am driving a Volvo daycab with a cummins ISX ENGINE. Rated at about 425hp. Have a single 28' pup with 12,000# net. Trailer is about 8000 tare. So 20k and the tractor is a single axle. Running flat, the dash meter is showing about 10. 4mpg average. 80 miles so far this trip. . see how it does going to Boise, id. . 350 miles

 

[EricBu12]

About 3/4 of the way too Boise, with several hills at full speed, no slowdown, a little headwind around Twin Falls, so far my dash meter says 9. 5 mpg. Amazing the comfort and ability of a semi. Even a day cab. . with a lighter rv, this would have been over 10 mpg. Great for a long haul retired traveler. .

 

[HBarlow]

Lots of full-time RVers over on the Escapees Forum own and praise retired OTR tractors for use in RV service. Many of them pull very large and heavy fifthwheel trailers.

A few of them brag about the creature comforts provided by Volvo tractors.

Some of the advantages they mention are the quiet, comfortable cabs, room to move around while underway, excellent fuel mileage, outstanding brakes, and the ability to sail up and over steep grades maintaining highway cruise speeds with the cruise control set.

 

[NIsaacs]

Yup, and when ya work on it, it takes a crane or cheater pipe..... :-laf



Nick

 

[EricBu12]

At boise now. . averaged 9. 4. . amazing. . now take a smaller 8. 3 daycab or rv truck I think it would be about the same. . this truck I drive usually has triples hooked to it for upwards of 105,000 lbs . . and 103 ft long.

 

[MChrist]

Yep, that's about what you'll get. I suppose if you figure that it takes X amount of fuel to make X amount of power to move X amount of weight with X amount of aerodynamic drag, there really isn't that much of a difference between our trucks and big rigs. The only factor not considered is the efficiency of the motor at the rpm/load you are running it at.
The semi's size is clearly not as aerodynamic as a pickup, but the hole it's punching in the air is big enough for the camper to slip through, so it's close to a wash.
My '97 Freightliner Century Class has a Cummins M11, and is right at 1,000,000 miles. I bought it with 750,000 miles and haven't had a stitch of problems with it. That's one difference to consider, though. Those trucks aren't being stressed at that point. Also, when parts do wear out at one fifth the rate, they don't cost five times as much as parts on our pickups.

 

[EricBu12]

Funny thing is also when truck by itself with wind deflector, still read 11 mpg max. . . . Return run with almost identical weight trailer and 2 empties, about 10K each, a short flat section was about 7. 5mpg. . .

So Id say like a 8. 3 medium Duty Cummins in a volvo or similar, with air-ride and all the comfort and capability and stuff, should be a very good long range, capable economical rig. ... just tow a smart car behind it or get a toyhauler to haul it in the back. . my 36' toyhauler has a 12' . . "garage"... perfect fit... when I get one later on.

 

[Barry]

I have buying medium duty trucks for one of my dealers. This is the latest unit I bought. The elderly gentleman that bought this one new only pulled his Mountain Air 5th wheel.

At 65 mph, the little 330 Kitty Cat was turning 1600 rpm. Air ride EVERYTHING just floated down the road. This is an FL50 and is only rated at 20K so no need for CDL. I took these pix in my front yard before I delivered the unit up to the dealership.

Freightliner Horse Trailer For Sale Used 2001 Truck Gooseneck Horse Trailer For Sale - Dixie Horse & Mule Co.

Disclaimer: This is not an offer to sell but for demonstration/information only.

 

[HBarlow]

Barry,

Owner of a truck like that wouldn't require a CDL whether it was rated 20k or 26k as long as he was pulling his own RV trailer. In many states, such as Texas, the owner would require a Class A Operators License.

 

[EricBu12]

Barry that is a sweet rig. For $48k very well worth it.

 

[MChrist]

... if it only had a Cummins...

 

[Barry]

Everyone that I bought last year had a Cat in it. I missed one in Calif. with a 330 MBZ... ... ... .....



This 330 Cat will run like a striped ape. I was well pleased with it.

 

[MChrist]

Just looking at the info on that truck. . 14,000 lbs is nothing for a 330 Cat. I have a 2001 Sterling with the 300 hp 3126, and it is 48,000 full and about 21,000 empty. It moves out just fine even when it's at 40,000 lbs. So add 10% more power and even pulling a 16,000 fifth wheel, it wouldn't be a problem. I'm just not a fan of the 3126 Cat... .