Should I put a cap/cover on my tow vehicle?

#1

My tire rack is pretty high on my little 14’ trailer. The car’s hood sits underneath it. The tire rack really sticks up like a sore thumb when I’m towing. With no tires in the rack I get about 12mpg. With a full tire rack I get 8mpg.

That’s $90 difference in the cost of a weekend at Rd Atlanta. Call it $120 difference for my typical month of a CMP event and an RA event.

I’m thinking about putting a fiberglass cap on my truck such that I could keep the tires in the truck’s bed. It would also keep other stuff in the bed more secure and out of the elements.

Is gas mileage a decent reason to get a cap? I can probably get one used for $400-$600.

#2

The number one reason to get a camper top is for the ladies. They think they’re hot.

I have no tire rack and since I like to bring everything in the garage to the track I’ve considered getting one. But realistically you can fit just about everything and anything you’d need under it in the bed of the pickup.

I talked to Patton about this since he knows about after market truck stuff. There are also locking tonneau covers, etc.

Personally I like the top, fits everything, lockable, etc. Did not hurt or help my gas mileage.

Mine is a Leer? Middle of the range, think I paid $500 or $600 new installed.

Someday I may trying bringing an air matress and sleeping in it as well. That is strictly theoretical at this point though.

#3

We finally get a chance to tell Ranger to PUT A LID ON IT! :laugh: :laugh: :laugh:

[size=1]Just kidding, Scott. You are my exploratory hero![/size]

#4

i’m about to pull the trigger on a new trailer, and was considering a tire rack but didn’t realize they had such a negative impact on mileage. do you have any pics showing how tall yours is? i’m wondering if a shorter one will make a difference since it will be faired behind the tow vehicle.

#5

The important thing about aero is the shape on the rear, not the shape of the front. Although that seems a litle counter-intuitive, consider the teardrop.

Current tow vehicle is a pickup, not the X5 shown.

A full tire rack adds prob 8" of both height and width to my rig. So maybe 5.5 sq ft more crossectional area.

#6

thanks scott. my tow rig is an excursion so i have a lot of frontal area already (and it’s very square in back) so maybe the rack won’t hurt me quite as badly. plus it’s a diesel so the extra drag should have a smaller impact on fuel burn. still, i don’t need the rack but it beats loading and unloading wheels from the cargo bay, especially if i choose to sleep in the back.

#7

I just heard about these a few days ago
http://www.airtab.com/en/
Many of the pictures are over-the-top as to where they’re used, but I could see putting them on the trailing edge of a trailer (anywhere there is a 90 degree angle where vortices cause drag behind them)
bruce

#8

Face it Ranger, you just need to ditch the girlie little Dodge tow vehicle and go buy one of Roger Penske’s 18 wheeler race car hauler rigs - with all the NASCAR downsizing, there has to be a few good ones for sale in North Carolina.

That way you can haul a fleet of Spec E30s to the track, in fact, you could quit your day job and just start one of those arrive & drive race car shops.

Discuss that with the Lawyer and let me know how it comes out… Does she know how to un-safety your 9MM ?

Otherwise I vote for the used Ford Excursion Diesel and a nice 24 foot enclosed race car hauler - she’ll think that looks good after the 18 wheeler proposal.

#9

I do need to ditch the girlie gas 1/2ton truck. But that’s going to have to wait. Until then I’m going to try to make myself keep the girlie truck.

Have the cap now. To my surprise I noticed a difference in engine strain immed. Going to fetch the cap the tranny kept trying to downshift at my chosen speed. On the way home with the cap, the tranny didn’t try to downshift.

http://jacksonville.craigslist.org/pts/1536771122.html

#10

Yep - that bump in the back of the cap should help keep your tires out of the air blast. I’ve also seen guys build a sheet metal or fiberglass nose on their open trailer - you can store the tires inside the nose and it protects the car from debris. Maybe more important on open cockpit formula cars than a door slammer.

If you think that your truck is wimpy now, just hook it an enclosed car hauler and see what happens. My old 06 1/2 ton GMC with a 5.3L would get about 6-9 MPG with my 20 ft enclosed - and about 14 with an 18ft open flat trailer - BIG DIFFERENCE IN AERO (and some in weight too). I think my 20 footer is about 3000 lbs empty & can hold up to 4000 lbs in cargo. (2 axles at 3500 lbs each). You pretty much tow in 3rd gear all the time with an enclosed - with the open it could use 4th on flat ground at 70MPH.

Jim

#11

I whine about my wimpy tow rig, but I can’t imagine having to tow up some real hills. I’m 2hrs towards CMP and RA before I hit a hill the size of a freeway overpass.