Aerodynamics

[greg334]

Ok i am pretty bore this past week and thinking ways to stimulate some conversaions so here is another questions for all of you straight truck and T/T owners/drivers.

What in your opinion and maybe experience is the truck that give the best aerodynamic performance - including drivability and fuel economy?

AND

a follow up question, what do you think would be a good fuel efficeint drive train?

Sorry for the misspelled words - had to type with a cat on the laptop.

 

[LDB]

I'd vote for an ISM S/T engine with 13spd as one of the most efficient powertrains. The KW T660 should be one of the most aerodynamic trucks along with the Volvo and Columbia. The Pete 387 is another but not sure it could be set up so it isn't too heavy on the steers. That's the same problem with the T2000. If I could wave a wand and have the truck sitting in front of me it would be the T660 with ISM powertrain and ICT or ARI sleeper.

Leo Bricker, 73's K5LDB, OOIDA 677319
Owner, Panther trucks 5507, 5508, 5509
Highway Watch Participant, Truckerbuddy
EO Forum Moderator
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Support the entire Constitution, not just the parts you like.

 

[X1_SRH]

I can only speak for the Freightliner products since that is what I am experienced with. I know that the Century class tractors were one of the very first big trucks to be wind tunnel tested - and it definitely pays off in fuel economy. I'm sure that the Columbia is every bit as good, if not better. In addition to the class 8 stretch, I have also operated internationals (9.5ish MPG) and Freightliner class 7 trucks (10ish MPG). My personal experience is that a Century class stretch with a C-10 and a 10 speed trans Outperformed all of them in both performance and economy (one of my last quarterly calculations was 11.8 MPG). The fuel savings offset the cost of a bigger and fancier truck. That doesn't happen often - but in this case it is fact.

Please keep in mind that all these numbers reflect driving a particular vehicle like I had to make it last forever - Smoothe and Easy!!!

Scott

 

[Paul56]

2nd vote for the Kenworth here. That is what we roll with.

 

[rode2rouen]

My '99 International 9200 is fairly aero, and the 400HP M11 (pre EGR ISM) Cummins is giving me MPG in the mid to high 9s. The rear axle ratio (2.94:1 w/ 10speed direct)is a bit off for max economy, but a taller drive tire will get it in ballpark (Cummins sez 1500rpm @ cruise speed and I'm turning about 1650).

I disagree with Leo's 13speed as getting the trans into HIGH GEAR as quickly as possible and then setting the cruise is the way to MAXIMUM fuel economy. Especially in a "D" type rig where the lower ratios are seldom, if ever, used. With a loaded GVW of 45800 out of a possible 46000, I never used the lowest 3 gears of my 10speed and never had to downshift on the PA TPK with that load.

I put AirTabs on the truck back in April, but I can't honestly say that they've helped the MPG (any gain is to the right of the decimal point). The tabs do make a marked difference in how the truck handles in crosswinds and such, so from the standpoint of the truck being easier to drive, they're worth adding IMO.


Rex

 

[greg334]

Thanks, the more info the better.

Talked to a pumpkin driver today and he said he is getting about 9 with his century and a 10spd loaded. He didn’t know what engine he had or didn’t want to answer but he said that he will be getting new pumpkin in a few months and it has an ultrashift.

So I have to add something else, what about an autoshift and ultrashift type trans?

 

[ATeam]

Jeff Jensen's Sept 1 article about aerodynamics will be of interest to readers of this topic:

http://www.expeditersonline.com/artman/publish/truck-aerodynamics.html

 

[Jack_Berry]

i still have nothing to impart from personal experience but some driver here has added trim tabs to the the end of his truck. i have been waiting to read an update of what he can tell us of the difference he has experienced.



Jack Berry