Tugboat mini camper
 

Hello, first post from a long time unregistered lurker.
( ok, that didn't sound right).

I need to tow my boat and also wanted a small camper so I am going with this 2007 Isuzu NPR, 109" wheelbase, 5.2 Diesel with 6 speed auto. The box was purpose built for TruGreen lawn maintenance franchisees and is no longer manufactured.

Throwing it out there. What do you think?

Welcome! :)
I think the box has potential, especially the already Kamm'ed rear. Extend that with a hitch-mounted boattail for extra cargo (when not hauling your boat), cover the rear wheels and the gap between the cab and box, and it could fit the template quite well.

When towing the boat, I wonder if you could have some fairings on the rear, extending the wake so the trailer is in it. Or mod the trailer to be a boattail extention.

Sorry, got carried away;)

I wonder how efficient the drivetrain would be for long trips... Are those single or dual wheels in the rear?

It's a dually. GVWR is 12500, though I will never load it that heavy. Still it has to have the tires to meet the rating sticker.
I'm thinking of a pool noodle solution to the cab/box gap. Wheel covers at the rear definitely.

How about a front air dam?

I have a lot of weight to pull out of her still. She currently weighs 7750 by the hyway truck scale locally. There's a big tank and pumps and a PTO to remove which I expect weigh hundreds of pounds.

Probably need to skid plate the undercarriage as well.

If I get 15+ mpg towing I'll be doing good.

Welcome.

Talk about streamlining a brick.

I'd ditch the backup mirror. Hows about a pan and tilt dashcam?

For the front corners: ecomodder.com/forum/showthread.php/pillar-guides-38341.html

For the mirrors:
https://s.aolcdn.com/dims-global/dim...ruck-006-1.jpg
ecomodder.com/forum/showthread.php/some-deep-thinking-getting-best-mpg-van-36862-3.html#post580506

The new back up camera and 10" dash display should be delivered today. Yes, the big mirror on the back corner needs to go.

Those unfortunate postal carriers. Don't they have enough to endure without adding the ugliest vehicles ever produced?

It was just the first pic I found. Here's the bus I ride around town:

https://southtownerotary.org/wp-cont...tion-1_lb.jpeg
southtownerotary.org/wp-content/uploads/2017/07/emx-bus-at-station-1_lb.jpeg

They're on long arms for situational awareness. Scaled down, you might be able to adapt duckduckgo.com/?q=swan+neck+fender+mirror&iar=images

edit:
Looking for cab corner turning vanes [AKA pillar guides], I found this article: www.driverknowledgetests.com/resources/reduce-fuel-consumption-using-truck-aerodynamic-aids/ that might be helpful.

https://www.driverknowledgetests.com...er-446x595.jpg

Others are internal ducts that look like air scoops and appear to function like an air curtain. They're not full height, just a central jet [across the door handles?].

Already sounds smarter than picking a random V8 rig. But anyway, most likely the tilt-cab makes it harder to get a more seamless transition from the cab to the body in order to improve aerodynamics.

Is it possible to re-register as a lighter, non-commercial vehicle? I understand that upping the weight limit would require tests, certification, but going down should be easier. That might allow you to go will single tires, which would reduce rolling resistance and slightly clean up aero.

I believe it's a liability risk for the retailer that drives the tire mounting requirements. The GVWR is stamped on the door frame. It's the same when you buy tires for a Corvette. You might never drive 200mph, but you still have to pay for tires that can.

There are Super Singles that will work but seems they are only available in Australia, or there abouts, and are prohibitively expensive. I could also get a set of inner wheels for under $400 and not mount tires on them. I'll need to be confident about the weight rating on the one tire option before I try anything so bold.

Future maybe change out the axle for something with taller gears and more wheel options but that's only if what's there breaks. She runs 2600rpm at 60mph which seems way too high.

ISUZU Cabover
 

Here's a link to NASA's 'Project Shoebox.'
They modified a FORD Econoline van, and reduced the drag coefficient, from around Cd 0.50, to Cd 0.238, with a 'nasty' boat-tail.
Rather than list all they did, I'll just let you experience it for yourself.
PS In the past, truck makers published their Cds. You may be able to find out, roughly, where you're starting from.:)https://history.nasa.gov/monograph46.pdf