Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - "Big rigs will have to slash fuel consumption by 23 percent".

p38fln · 08-10-2011, 11:21 AM

Yes it's possible, and without doing a thing to the engines. Consider the number of absolutely ridiculous aerodynamic designs available for sale *right now* - the Kenworth T-800 for example. Big, square hood, absolutely no curves to the entire vehicle other than the fenders. It's only aerodynamic features are a sloped hood and windshield.
Their T-660 (A so-called aerodynamic truck) is better - the hood is curved and sloped, the grille is as small as possible to still get airflow - but the sleeper is just like a parachute hanging from the back of the truck.

Then look at the Freightliner Coronado and Kenworth W-900 - these two relics should have been retired YEARS ago, although at least the Freightliner has some curves and aero features. There's absolutely no need to have a rolling brick like these on the highway, other than that people will buy them for their looks. I think the W-900 has possibly got the worst aerodynamics of any truck available right now. EXTERNAL air cleaners? Who does that anymore...
I just realized that both KW and Freightliner have snuck air fairings onto the back of these trucks - I'm assuming they figured none of their 'real truck' buyers would notice

Some examples of modern, aerodynamic trucks? The KW T-700 and Freightliner Cascadia (Everybody makes aerodynamic trucks, I'm trying to keep this post short)

Can't find a good picture of a T-700 quickly, here's a Cascadia - Notice all of the aero features missing from the Coronado and W-900 - Exhaust located behind the cab instead of stuck into the wind, air fairings over the fuel tanks ('skirts'), the hood is sloped and narrow towards the front and wide at the back to encourage airflow over and around the cab.
Also notice the top of the cab is curved instead of square like the W-900 to encourage the air to flow more easily over the top of the trailer the tractor is pulling

The aerodynamic differences of these trucks can easily see a difference in fuel economy of at least 20% if not more. We've actually seen some significant differences on truck makes here - sometimes as much as 25% from one design to another.

Also, the fuel economy standard for trucks will be fuel burned per ton of freight hauled at (i think) 75% capacity - so a larger truck won't have a penalty as long as it can haul more freight.

08-10-2011, 11:21 AM	#7 (permalink)
p38fln EcoModding Lurker Join Date: Apr 2011 Location: Eau Claire, WI Posts: 79 Escape #2 - '13 Ford Escape Titanium C-max - '17 Ford C-Max SE Thanks: 0 Thanked 11 Times in 7 Posts	Yes it's possible, and without doing a thing to the engines. Consider the number of absolutely ridiculous aerodynamic designs available for sale right now - the Kenworth T-800 for example. Big, square hood, absolutely no curves to the entire vehicle other than the fenders. It's only aerodynamic features are a sloped hood and windshield. Their T-660 (A so-called aerodynamic truck) is better - the hood is curved and sloped, the grille is as small as possible to still get airflow - but the sleeper is just like a parachute hanging from the back of the truck. Then look at the Freightliner Coronado and Kenworth W-900 - these two relics should have been retired YEARS ago, although at least the Freightliner has some curves and aero features. There's absolutely no need to have a rolling brick like these on the highway, other than that people will buy them for their looks. I think the W-900 has possibly got the worst aerodynamics of any truck available right now. EXTERNAL air cleaners? Who does that anymore... I just realized that both KW and Freightliner have snuck air fairings onto the back of these trucks - I'm assuming they figured none of their 'real truck' buyers would notice Some examples of modern, aerodynamic trucks? The KW T-700 and Freightliner Cascadia (Everybody makes aerodynamic trucks, I'm trying to keep this post short) Can't find a good picture of a T-700 quickly, here's a Cascadia - Notice all of the aero features missing from the Coronado and W-900 - Exhaust located behind the cab instead of stuck into the wind, air fairings over the fuel tanks ('skirts'), the hood is sloped and narrow towards the front and wide at the back to encourage airflow over and around the cab. Also notice the top of the cab is curved instead of square like the W-900 to encourage the air to flow more easily over the top of the trailer the tractor is pulling The aerodynamic differences of these trucks can easily see a difference in fuel economy of at least 20% if not more. We've actually seen some significant differences on truck makes here - sometimes as much as 25% from one design to another. Also, the fuel economy standard for trucks will be fuel burned per ton of freight hauled at (i think) 75% capacity - so a larger truck won't have a penalty as long as it can haul more freight. Last edited by p38fln; 08-10-2011 at 11:35 AM..