Originally Posted by ddbck
It towed my older heavier toy hauler very good even up the steep Mts. The Shamrock is well under the 11,200 lbs my truck is rated for.
Not talking about weight. My fully loaded 21SSL is but a wisp 'o nothing weight wise to my massaged diesel excursion. However, at hiway speeds, I find the mighty 7.3 has to work noticeably harder towing the Roo. On flat level ground at 70 mph, unloaded I usually run about 6-7 pounds of boost at roughly 700-800 degrees on the exhaust gas temps. With the roo, I run 13-15 pounds boost at around 1100 degrees EGT. That quite a bit more work.
I've hauled a 22' flatbed with two built Suzuki Samurai rock crawlers on in (about 9K pounds total) and barely knew it was back there. But get the Roo up to 65-70 mph and it tows like it weighs twice as much. I think the front deck keeps the air off the back of the Exy from smoothly going over the top of the Roo, and it hits dead square on the front.
In other words, the 21ssl is like towing a big parachute.