Another data point, considering your statement here:
Quote:
|
Originally Posted by Chance
To my previous question/point that Axis could/should do better in fuel economy, if compared by weight alone (and I know it's more involved than that) your 15,000-pound trailer combo getting 8 MPG would suggest around 10.5 for the Axis, not 8.5 MPG.
|
Before our 5er we had a 27ft travel trailer that weighed about 2,000lbs less than the 5er. The F-250 actually got 1 mpg better mileage pulling the 5er than it did the TT. (The F-250 was a 1999 V-10 with 2-valves, the constricted factory exhaust, and a 3.73 rear, the F-350 was a 2008 V-10 with 3-valves, a far less restrictive factory exhaust, and a 4.10 rear.)
In actuality I think the F-350 + 5er was a pretty aerodynamic combo:
(especially when compared to our previous F-250 + TT and the Axis)
Thus my observational data would suggest that, at some point, aerodynamics affects mpg more than weight (I'd guess that weight matters more during acceleration and deceleration events and wind resistance is a greater affect during steady state highway driving).
Compare the above image with:
The Axis is just a brick--I'd guess all the air resistance from the car back there doesn't affect much as its in the vacuum (so to speak) behind the coach since our mpg in the Axis doesn't really change noticeably when the car is back there or not.
Another thing to consider as well: The F-53 chassis is sold with the 3-valve V-10 and the E-Series chassis (Axis/Vegas) is sold with the 2-valve V-10 (362 vs 305 hp:
https://en.wikipedia.org/wiki/Ford_M...gine#2-valve_3).
(Not really trying to argue any point, just adding more information to the discussion.)
Thor Forums
