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slowmover · 10-07-2011, 01:08 PM

Thanks for clearing up my misunderstandings.

The 200-mile section of IH-10 from Fort Stockton to Junction, TX is already 80-mph the past five years (and some lesser known roads); maybe more of it by now. 85-mph has been approved by the Legislature. Signs will go up at DOT's pleasure. Run 80 and you will be passed by 2 out of 10 vehicles according to DOT.

Should a pickup MPG test not be done with a standard and uniform load – say 800lb of sand bags or the like? I often wonder about my own claims which are done (mostly) unloaded except for the aforementioned fat butt.

500-lbs in bed, full fuel with driver, and 4000-lb U-Haul 12x6x6 enclosed trailer on a proper hitch (500 TW). This will cover half-tons plus 3/4 and 1-T pickemups fairly well. Certified scale weights to keep tongue weight inside factory parameters (and consistent among vehicles). Trucks should be weighed unhitched, but with driver, fuel and bed load prior.

(Might go to 9k for the bigger trucks, but not less than about 5k for the smaller. The real problem is in setting up a weight-distribution hitch properly across a range of vehicles. So an agreed-upon TW needs to be set, thus trailer max load determined. Trailer TW is the towing rating brick wall as bed payload [rear axle] is limited).

Realistically, this covers what a pickup truck can do. A reasonable analogy is to a car with four adults and luggage (up to near rated capacity).

The U-Haul means uniformity among test vehicles. A prescribed number of full stops and accelerations would need to be counted in. Rolling resistance would be highlighted.

Terrain & altitude are the real problem for cross-country comparisons.

There isn't much aero penalty with the big U-Haul is "the problem". I ran empty and loaded foru times over the same 350-mile route and still saw 18-19 mpg versus 24-27 solo (7,400-lbs versus 13,500 of a 20k GCVWR). A 25 to 30% fuel penalty.

With an RV (conventional hitch) 30-40% mileage reduction is the expected range, gas or diesel.

It makes a bit more sense to baseline a particular vehicle, and then when loaded according to an agreed method to suss out changes in RR and AR to find percentage changes.

.

10-07-2011, 01:08 PM	#23 (permalink)
slowmover Banned Join Date: Oct 2009 Location: Fort Worth, Texas Posts: 2,442 2004 CTD - '04 DODGE RAM 2500 SLT Team Cummins 90 day: 19.36 mpg (US) Thanks: 1,422 Thanked 737 Times in 557 Posts	Thanks for clearing up my misunderstandings. The 200-mile section of IH-10 from Fort Stockton to Junction, TX is already 80-mph the past five years (and some lesser known roads); maybe more of it by now. 85-mph has been approved by the Legislature. Signs will go up at DOT's pleasure. Run 80 and you will be passed by 2 out of 10 vehicles according to DOT. Should a pickup MPG test not be done with a standard and uniform load – say 800lb of sand bags or the like? I often wonder about my own claims which are done (mostly) unloaded except for the aforementioned fat butt. 500-lbs in bed, full fuel with driver, and 4000-lb U-Haul 12x6x6 enclosed trailer on a proper hitch (500 TW). This will cover half-tons plus 3/4 and 1-T pickemups fairly well. Certified scale weights to keep tongue weight inside factory parameters (and consistent among vehicles). Trucks should be weighed unhitched, but with driver, fuel and bed load prior. (Might go to 9k for the bigger trucks, but not less than about 5k for the smaller. The real problem is in setting up a weight-distribution hitch properly across a range of vehicles. So an agreed-upon TW needs to be set, thus trailer max load determined. Trailer TW is the towing rating brick wall as bed payload [rear axle] is limited). Realistically, this covers what a pickup truck can do. A reasonable analogy is to a car with four adults and luggage (up to near rated capacity). The U-Haul means uniformity among test vehicles. A prescribed number of full stops and accelerations would need to be counted in. Rolling resistance would be highlighted. Terrain & altitude are the real problem for cross-country comparisons. There isn't much aero penalty with the big U-Haul is "the problem". I ran empty and loaded foru times over the same 350-mile route and still saw 18-19 mpg versus 24-27 solo (7,400-lbs versus 13,500 of a 20k GCVWR). A 25 to 30% fuel penalty. With an RV (conventional hitch) 30-40% mileage reduction is the expected range, gas or diesel. It makes a bit more sense to baseline a particular vehicle, and then when loaded according to an agreed method to suss out changes in RR and AR to find percentage changes. .