Postby CPLTECH » Mon Sep 16, 2013 10:51 am
Last winter bought a 2003 Amerilite 21’ 3300# empty, 7.5’ wide. Took it 160 miles to Zanesville using I71 & I70 a week ago. Got 13.2 mpg going & 12.5 coming [headed into wind], with prem fuel. Tires on the PF were at 40-45psi, camper at max sidewall, 50 psi. Set the cruise @ 55 since it is more capable than my foot to maximize MPG. Found that a number of the trucks that passed me weren’t going much faster. May not be the case where you live. Used 4th gear, but on flats or downhill used 5th. On the mild rolling hills the water temp would go up to 213º in 4th. On the flats, 4th avg 207, yet in 5th was ~200. Shows the inefficiency of the torq converter. Torq conv is programmed to lock-up in 3rd & 5th only. 4th is slush-a-matic.
As for the chosen speed, when I brought it home I did 60MPH and got 10 MPG in 4th. With a similar trailer, doing 60-62 with a ’98 Tahoe (5.7L) it would avg in the low 11’s. Back in 2000, went to Mouse World with an S10 Blazer (4.3L) and got 13 MPG but only because I kept the speed 55-57, otherwise it would start to overheat. So, my thoughts are from these observations are that much over 55 and you really put a strain on a power train and pay dearly if MPH is exceeded, just that a larger truck can dissipate the energy better although expressed in poorer mileage. I recall a thread in a RV forum where owners were upset that the campers shaped like an upside down bathtub also got lousy mileage above 55. More mfg are designing with aero in mind, if willing to pay the upfront price. Frontal wind resistance & rear drag affect performance more so than weight. Too much length can be treacherous without sway bars and WD hitches.
I feel that the 4.0L engine in the Pathfinder is strong, just mated with a less-than-stellar trans. For that reason I monitor the temp with a ScanGauge2. For some reason it won’t read the trans temp. When it comes to replacing this PF, others have 6 & 8 sp trans and maybe by then the CVT in the 2013 & up PF will have some of the kinks worked out. Or if I want to stay in the Nissan family, Xterra has a 6sp manual…