JoeM 7,873 #51 Posted April 12, 2022 3 hours ago, Pullstart said: tune vs no tune kids right bot to change the tune! We need a wind tunnel, or a stiff wind and a smokey campfire to pull up to. Share this post Link to post Share on other sites
Ed Kennell 38,158 #52 Posted April 12, 2022 (edited) 11 hours ago, Maxwell-8 said: The rear matters as much as the back. You mean front Max? Yes the square rear probably causes more drag than a square front. Edited April 12, 2022 by Ed Kennell Share this post Link to post Share on other sites
Pullstart 62,840 #53 Posted April 13, 2022 18 hours ago, wh500special said: I have never understood how a tune can change that physical reality very much. I can see getting more power from the engine - especially a diesel - by force feeding it fuel and having it run more fuel-rich than intended by the manufacturer but I don't understand where the simultaneous mpg boost can come from. The manufacturer has to tune the engine to meet durability, emissions, and performance goals so they probably leave something on the table with respect to any one of those issues to accommodate the other two. I'm not against tuning (to the point where emissions are still in check) and I think the performance gains are easy to feel and substantiate, but I am skeptical they can also improve fuel efficiency at the same time. It seems unlikely that small software shops can beat the automakers at their own game. Steve Addendum - I went back and used my arbitrary 100-hp power requirement from above and did some back calculating...if that happened to be the power demand at 60 mph it would translate to a fuel economy of about 10.8 mpg. If it happens at 55 mph, then the fuel economy would be about 10 mpg. I wonder if this is close to what you see, Kevin? @Pullstart I believe having “new” technology, the tuner shops can control timing, injections per power stroke, etc, to make what fuel is added to the cylinders burn more efficiently, but that’s why people like me let people like them make the big bucks. Most times hauling, I get pretty dang good mileage. Most times recording though, I HAD a travel trailer that was about 3’ lower than I do now and a couple thousand pounds lighter too. The fifth wheel happens to be quite large. I will plan for about 10 mpg but I’m hoping this injector swap will maybe get me 12? We pulled the toy hauler out yesterday. I can’t expect too great with this behemoth! 1 Share this post Link to post Share on other sites
Pullstart 62,840 #54 Posted April 13, 2022 (edited) 18 hours ago, wh500special said: Edited April 13, 2022 by Pullstart Double post… Share this post Link to post Share on other sites
squonk 41,079 #55 Posted April 13, 2022 Search Banks Power on YT. All kinds of good stuff! Share this post Link to post Share on other sites
WHX?? 48,815 #56 Posted April 13, 2022 35 minutes ago, Pullstart said: 10 mpg but I’m hoping this injector swap will maybe get me 12? Now your talking my language! Is that beast that much taller?? Share this post Link to post Share on other sites
Pullstart 62,840 #57 Posted April 13, 2022 4 minutes ago, WHX?? said: Now your talking my language! Is that beast that much taller?? It’s 13’3” high. One big wind sail, but it tows a whole lot nicer! Share this post Link to post Share on other sites
Handy Don 12,216 #58 Posted April 13, 2022 Plus the A/C units and vent on top are not helping. 1 Share this post Link to post Share on other sites
wh500special 2,170 #59 Posted April 13, 2022 (edited) 10 mpg with that behemoth wouldn't be so bad. At least with the crew cab and the storage bay in the camper you can take everything and everybody in a single load. For a family of four that would be like each one of them driving a car that gets 40 mpg By complete chance, I think I was pretty close on my guess that it would take about 100 actual HP to drag that thing down the road at highway speed. Ought to be able to pull it with a Chevy Sonic on flat ground if you can figure out a way to connect the hitch. Perhaps the picture below will give you some ideas. But those hills are gonna get you. Steve Edited April 13, 2022 by wh500special 2 1 Share this post Link to post Share on other sites
Pullstart 62,840 #60 Posted April 13, 2022 @wh500special I think I’d need a HD spring package for that Sonic… or V Dub.. 1 Share this post Link to post Share on other sites
8ntruck 6,998 #61 Posted April 14, 2022 I made the trip from Michigan to our Missouri location today. I saw lots of semis with a foldable fairing on the back of the trailer. Looks like the fairing gives the back of the trailer a couple feet oftaper - probably reduces the turbulence the square corners of the trailer cause. The brand on these was Trailer Tail. I wonder if something like that would help your toy hauler? 1 1 Share this post Link to post Share on other sites
