We have a very tall TC we haul all over the state. Average gas mileage on our rig drops from ~11 mpg (in town)w/o TC, to 8.4 mpg (highway) when hauling the TC. The TC is a Host Mammoth and is basically a huge windsail creating immense drag. Depending on headwind, at speeds of ~63+ mph, we get a loud whine from wind getting into the area between the top of the truck cab and the bottom of the cabover and then escaping out near the front jacks.

So here's the question: would an aggressive hood deflector help out with the whine at speed and potentially also increase fuel mileage? Have any of you tried anything specific that worked?

A friend at work told me he 'knew a guy' who owned a metal fabrication shop and had a large TC. This guy had created an adjustable aluminum scoop/deflector that he installed on his hood and when properly set, claimed he recovered 1-2 mpg's and reduced noise, because the air wasn't hitting at the windshield anymore and getting trapped, but was moved up to hit high on the TC nose, then went up and over.

My buddy is usually not full of crap, and it sounds legit, but I thought I'd check with you folks and see if any geniuses here have done something real and wouldn't mind sharing.

 

There was a big ta-do a few years back on the NATCOA forum about making the TC more aero-friendly and a lot of people did this type of air foil to eliminate the turbulence between the truck and TC.



I never made one and I'm not sure if there was any gain in mileage, but it was stated that it did a very good job keeping the bugs off the front bulkhead of the TC and dramatically cut down on the noise and corrected the air flow around the cab. Unfortunately were pushing a brick down the road and I notice a substantial drop in mpg above 65 mph.

 

I've been trying to get the DW on board to get a Mammoth when we retire and not a 5er.

 

Interesting solution on that air foil. Anybody tried that?

5er's have their place to be sure but IMO, you won't regret a Mammoth if you go that way. It's like a luxury apartment on the back of your truck. We wanted to be able to get off road, actually turn around easily in a parking lot or campground, and be able to use smaller campsites. Plus, I don't have all the extra maintenance that comes with extra sets of axles. Just make sure you have enough truck payload capacity to carry one, cause they're heavy as heck.

 

We still have a little while and till then the S&S works, and yeah I would use at least an F450.

 

Years ago a company made a air filled tube type thingy went between the top of the cab and behind the cab.
i think the one for the roof was mostly intended as a shock absorber, not positive.

 

I have a buddy of mine (on his GMC- UGH!) He puts a pool noodle between the camper and the truck cab- reduced his wind noise considerably. and you can get them for a buck at the dollar store.

 

Did he put the pool noodle on top of the cab or behind the cab?

 

Behind the cab. No glue screws or duct tape just set it in there.