Originally Posted by saskrick
If it shifts from 3 and 4 alot then I wouldn't use D or 4th. This is my preference. Trannies get way more hot with constant shifting vs not shifting. Going down the road with a few more revs wont hurt anything and you'll maintain your speed better. Your load is not too big though, so if it stays in 4th most of the time you should be ok.
Great answer!! Just thought I'd add that we towed our pop-up in overdrive all the time with an F150. There's not much wind resistance when it is sitting right behind a pickup.
2012 F150 FX4 Ecoboost, 2016 Surveyor 274BHS
2003 Yamaha FJR1300, Demco Premiere Slider
1969 John Deere 1020, 1940 Ford 9N, 1948 Ford 8N
Jonsered 535, Can of WD-40, Duct Tape
Red Green coffee mugs