Your Experience With Cabover Fuel Mileage

The brick wall is actually more aerodynamic since it’s all in one spot , and not 8 separate things for the air to go around : fenders hood windshield stacks sleeper etc

would not surprise me to see truck manufacturers going back to that , kind of like the football helmet peterbilt cabover with a slightly angled front .

Id not be surprised to see one like the Pete with a moveable front , that could be extended and hinges out for max aerodynamic rolling but retracts for easier maneuverability in tight spots . also never figured out why the side spoilers couldn’t telescope slide back to the trailer at highway speeds and automatic retract when the rig slows down .

 

I have always wondered this!

 

I’ve heard from many old timers that drove both coes and conv’s in the 60’s and 70’s that they didn’t see any difference in mpg. One guy had both at one time with 1693 cats and they both got the same mpg doing the same things.
Many guys have said that the k100 aerodyne did better and was quieter in the wind than the w900 aerodyne.
There has also been many debates about the most aerodynamic coes being the old IH Emeryvilles built from ‘58-‘65. Everyone that had one back in the day says 8mpg out of an old Non-turbo Cummins NH 220 was very common.

 

@OLDSKOOLERnWV

 

You can get right around 6.

 

I'am not looking to start a disagrement.. just wondered if you had any links to support that.?
Because to me a crapover is like putting a flame piece of wood in front of a fan verses a conventional has a more angular slop to it

 

Once the front of a cabover was through the air it was through the air. If the trailer was tucked up close then the air could continue down the side of the cab and trailer with very little disruption, the grab handles were all that stuck out for the most part. It’s not a coincidence that as the fuel economy standards come into play that the narrow cabs and exposed air cleaners are being phased out in favor of cab sections nearly as wide as the sleeper.

I’d be curious what JB and Schneider were doing for fuel economy back in the 80’s with their mostly cabover fleets. Of course with the 55mph speed limit it wouldn’t be a fair comparison to running one 10mph faster today.

The size of drivers these days is what will keep a modern cabover from making a comeback. It’s a work comp issue waiting to happen. The Argosy was ahead of it’s time with the fold out stairs I suppose.

 

They got 4-4.5 out of the busses. But that was only because they listened to the accountants and bought 290’s instead of 350’s or 400’s.

 

The trailer you pull will have a bearing on fuel mileage as well as your right hoof.

For the most part, with that wheelbase you should do decent even with a box behind you, as long as you don’t try to run wide open 100% of the time. I’d cruise along about 1550-1700 rpm and see how it performs. You should be around 5.25 to close to 6 mpg I’d think.

I’ve gotten 5.25 with my hot Big Cam running a lot of 65mph in Indiana @ 81,000 gross. But I’ve also got a lot of 4.75 running 70mph in the Hillbilly state and surrounding areas @ 70,000 gross. Course that’s in my W9, but point is, you’ll get different readings according to your terrain as well as how you operate the hammer in the floor. Sometimes you only need your big toe, not your whole foot.

Back when I drove the 1988 K100, I could get 5.0 - 5.25 with a 365 Cummins / 9 spd / 3.55 cogs on 24.5 tall rubber….. and out pull a 3406B @ 400hp in a 379 doing it. That pissed Underdog off so bad he couldn’t stand it when I slowly walked around him loaded on I-79!!

It’s not just the truck that makes a difference, it’s the driver as well, never forget that….!!

 

Here in the states we used the left turn signal a lot, mainly because of JB Hunt and their underpowered fuel squeezer Cummins in those International cabovers.

Them and Schneider were just everywhere, mostly rolling slow pulling a mountain……

 

Schneider Barrels. I think thats were the nick name for the orange construction barrels come from. When you saw a pumpkin trailer ahead in the distance you knew you had to treat it like a construction zone and merge into another lane to get around them.