Quote:
Originally Posted by RenaissanceMan
Doing my 1st tow gig to the track this weekend with the X5. Do most of you with automatics tow in Steptronic mode? Does it alleviate some strain on the transmission?
|
I tow almost exclusively in Step mode. For most highway towing, I keep it in 5th up to 70mph before letting it go to 6th. And even then, for anything more than just slightly hilly terrain, I just leave it in 5th. If I leave it in D or S, at 65 on the highway it's constantly up and down shifting. And shifting is slip which means more heat in the trans.
Pulling my track car on the open trailer, 4300 lbs with tools and tires on the tire rack, I'll get 11-12 mpg at 75-80 in 6th. If I slow it down to 70, I'll get 11.5-12, regardless of whether I lock the cruise in with 5th or 6th gear. At a steady 65, I can't use 6th at all, so have to keep it in 5th for about 12 mpg.
Keep in mind that peak torque on the 4.4 is somewhere around 3400 rpm so you want to be somewhere in the 3000-3500 range for pulling performance. In my X5, 3000 in 5th is about 72, but shift to 6th and it's just 2300, far off the torque and hp curve.