[rank]

Originally Posted by TomB985

For a specific frontal area, you are claiming that aerodynamics don't play a major part......<snip>.... it stands to reason that for a given sleeper height, some shapes move through the air easer than others.

I feel like I am banging my head against a brick wall trying to get this point home to you. I am NOT comparing identical frontal areas, nor am I comparing given sleeper heights. I AM SAYING THAT A LONG HOOD WITH A FLAT TOP BUNK WILL GET THE SAME OR BETTER FUEL MILEAGE THAN AN AERO TRUCK WITH A HIGH RISE BUNK.

I'd love to see a study comparing a KW W900L with a T660. Both can be equipped with the exact same sleeper and wheelbase arrangements, only a different front end. Put each trucks, exactly identical with the exception of the nose, through some real world testing...

W9's don't have side skirts and rear exhaust. Like I said about 10 posts ago. Put Columbias with high rise bunks against the FLD120 flat tops I posted above.

and I'd put some serious cash on the aero for the winner....

I will put same cash on the FLD 120 flat tops.

Everyone bashes the long hoods and all I am trying to suggest that there is more to mileage than the length of the freaking hood. I bet a pencil nosed autocar or 359 with a flat top will get good mileage too.

[TomB985]

Okay, okay...I'll stop arguing now.

Never drove a long nose flattop, so I really can't say much about those. I was more thinking of a comparison between trucks nearly identical in overall height, which was not the point you were trying to make. My mistake!

[Bandit102]

Well, I have 2 T-600's, a Century and a Classic. I don't have governors on any of them, but they all do similar fuel mileage. The Classic, in fact, has the biggest engine - 525 Cummins, 13 speed, 3.58's on Tall 24.5's. It does the best of the whole fleet (all the others are 470 - 475 hp) at 5.8mpg during the last 3 months. Of course, I pull a flat with it, whereas the other 3 pull reefers. The 470 Cummins T-6 and the 460 Cummins Century all get 5.3 to 5.5. The 475 Cat T-6 gets 5.2 or so.

There may be some big difference running at say 60 or 68 mph - I don't know. But running 75 or so, I see no difference. Thing is, when I run the Classic through IL, IN, OH etc. I see NO fuel mileage difference what so ever as opposed to running 75. Different gears and different RPM in the different operating environments may contribute to that.

Of course, everyone else I talk to with trucks spec'd the same as mine always get 2 mpg better than I so go figure.

[rank]

Originally Posted by Bandit102

Well, I have 2 T-600's, a Century and a Classic. I don't have governors on any of them, but they all do similar fuel mileage. The Classic, in fact, has the biggest engine - 525 Cummins, 13 speed, 3.58's on Tall 24.5's. It does the best of the whole fleet (all the others are 470 - 475 hp) at 5.8mpg during the last 3 months. Of course, I pull a flat with it, whereas the other 3 pull reefers. The 470 Cummins T-6 and the 460 Cummins Century all get 5.3 to 5.5. The 475 Cat T-6 gets 5.2 or so.

Got a high rise bunk on that classic or a flat top?

[Bandit102]

The classic has the condo sleeper. really tall. So does the century. 1 of the KW's has the standard aero sleeper without the airfoil and the other one has the airfoil on it.