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Old 10-15-2012, 06:55 AM   #12 (permalink)
slowmover
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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)
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Bed topper versus bed cap: Make some guesstimates on cubic cargo capacity needed. Same for weight: total number of passengers plus personal gear.

1] Take truck to certified scale and weigh with driver + full fuel (and any items which will be aboard permanently). This is the adjusted empty weight.

2] Remaining cargo capacity will need to controlled. The Dodge Towing Guide will show factory weight. Show us the numbers for your model.

3] Next step is tires & brakes (examination plus repair/replace) and loading the truck with representative weight. Brake drag needs to be eliminated if present.

On the scale one needs to get the per wheel position weight in order to set the best tire pressure according to the vehicle manufacturer specs (and in reference to the RMA numbers). Get the numbers dead on.

4] With that representative weight, one needs to do some "driving around" to see if any play exists in steering/suspension components. Transient response at highway speeds, braking into a corner, etc aren't just for safety, but keeping FE high. Trucks suffer in transitions from one state to another, and not just in acceleration/deceleration.

Cargo securement is critical. Even if the truck rolled over, the cargo should not move significantly.

Etc.

As to highway FE, calculate the amount of time actually spent at top travel speed without accel/decel/stops for breaks, fuel, food, etc, on a few representative trips. Then some time looking at all other engine-on time.

A truck is best used by limiting engine hours. Route planning is central to best use. Know all stops in advance, etc. No "hey, pull into that convenience store ahead, willya?" requests honored.

Aero changes are fun, no doubt, but the above (which is barely a sketch) underlies all the rest. The "mechanical baseline". 1/2T trucks are load limited. I'll guess that your gear/pax weights may put you at the limit. So calc first, and buy second.

Etc.

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Last edited by slowmover; 10-15-2012 at 07:02 AM..
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