Class 8 Trucks

[SmartTrucker]

Anyone out there that's made and tested fuel savings on class 8 trucks by way of aerodynamic and/or powertrain changes?

I'll try to throw up some pictures of our different tractors and list some changes I'd like to do to improve them. Most of them would be pretty simple and obvious changes. Currently I might as well be taping plastic bags to the sides because that's how obviously stupid things were designed all in the efforts of style.

The stacks on most of our trucks are currently just behind the doors and I think the benefit would be quite huge if I was to move them behind the sleeper. I have no idea what kind of mileage improvement I could expect on the first obvious fixes but I'm looking forward to finding out now if I can only get the boss to agree!

Looking forward to hearing any ideas or knowledge people have on the subject

[trikkonceptz]

I would love to tackle this project head on. I know there is room for improvement on these large trucks. However, the first change has to be with your drivers attitude towards saving you guys diesel.

Have to started keeping fuel logs? I would start there. Establish a before baseline with each individual truck and get the cooperation of the drivers. Explain what you are going to do and why. Heck if possible try implementing an incentive program for participation and improvement.

After that there are many tweaks that can be done before you get into altering the trucks. Driving techniques and driver attitude may get you the svings the company needs.

I would be more than happy to help you pro bono of course, so drop me a pm if you like and we can get a more technical plan going. Because if we can make this work then we have a blueprint any of us can market to fleets in need.

[SmartTrucker]

Hey trikk thanks for showing your support.

Yes I forgot to mention we did put a fuel saving incentive program together and implemented it 2 months ago as well as a dwms (don't wreck my *&#) bonus.

[trikkonceptz]

So when you get a chance, post up a picture of these bad boys, having a solid background with tractor trailers it would definately be cool to try and apply some ideas to these beasts.

[SmartTrucker]

Here's some stuff I'm currently running by the boss. I'm thinking of running one truck as more of a prototype for possible fleet wide changes.

2 of our older trucks are Columbia model freightliners with Mercedes engines that are perhaps a bit underpowered for the job but are lightweight and aren't as bad aerodynamically as our more classic styled trucks. There also the trucks most likely that the boss would let me make any changes too however unlikely he is to period.

1) move the 2 exhaust stacks from the side of the trucks to a single stack behind the sleeper

2) the air breather is currently under the hood which is better then the outside but I think we are pulling in warm air from beside the engine. With what could be a small bit of fibreglass work I think we can pull that air from the outside instead which should give us a power boost.

From there I'm not sure except some other smaller projects like possibly moving antennas/horns/covering up some holes in the bumpers that serve no existing purpose and perhaps shedding some unneeded weight.

We currently have regular tire service that is supposed to be on top of keeping tire pressure up but I sometimes suspect this isn't happening as well all our newer trailers have a psi system that in theory should be keeping are tires at the proper inflation.

[SmartTrucker]

Also I have to be roughly sure that there is going to be a positive return on investment it is a business after all it's not like the truck has an unlimited life span to endlessly recoup money.

any ideas are welcome though throw them out there please.

[trikkonceptz]

I'm sure you have weight restriction to deal with too ...

What techniques do your drivers use now? Do any of them coast to stops @ idle? Do you have to downshift to brake or are the air brake setups enough to stop the truck? How much unnecessary idling do they do? I don't mean shut them off at lights or anything, but do they unload with the truck running? leave them on during lunch breaks, etc?

The tires could be your first focal point, now keeping them @ max psi to sidewall may be the safest way to go, around here truckers use re-treaded tires and I would never trust those at any psi.

I agree removing the stacks will help. Simply pipe or dump the exhaust under the truck or out the side and away from the main air stream will save weight and start giving small benefits.

How about wheel discs? Switching your lighting to LED's. The less the alternator has to work the better ...

oh and pics pics pics ... stop teasing us and making us guess in the dark ... LOL

[SmartTrucker]

Unfortunately we don't have tracking units at this point to watch there driving habits. Once inawhile we get them hooked up at the shop and get a readout telling us there breaking habits, idle time etc.

With the new performance system a few of them are really trying to make the goals so I don't imagine they're idling like they used to do.

I should send out a common sense driving habit newsletter with some fuel saving ideas as well. I've already told them what slowing down by 10mph would do for them.

Also we haven't ran recaps on our company trucks for a few years we don't trust them either.

I'm working on the photos I know we have some on one of our computers

[SmartTrucker]

Oh and yes we are rocking LED's

[trikkonceptz]

Are any of them over night sleepers?

[Clev]

Very good ideas so far. I can't stress enough the incentive plan. I can tell you from firsthand experience that people drive much differently when they're not footing the fuel bill (or in your case, getting a bonus for NOT using a lot of fuel.)

I think a hybrid system would be ideal for these trucks, as they waste fuel spinning up the turbocharger heading uphill, and then waste the momentum with the Jake brake downhill. Running the engine to keep up the electrical, air and A/C while parked is another problem easily solved by such a system.

The problem, of course, is the weight of the batteries. With a mandated 80,000 pound limit, every pound up front is a pound that can't be carried (for profit) on the back. Maybe the NTSB can come up with rules that allow the extra weight of hybrid systems to exceed the 80,000 threshold (say, 80,000 max allowed, plus up to 2,500 pounds of batteries.)

As to your problem, is there any way to enclose what's loaded on the flatbed? Maybe a curtain-side trailer with a boattail on the back, like these?


Tim

[trikkonceptz]

If your class 8 is the typical semi here in the states then here are more suggestions ...

Fenders for the rear wheels of the truck and perhaps trailer. Design fiberglass fenders that cover as much of the wheels as possible, even side skirt style, thus reducing air turbulence from that part of the truck.

Also are you running dual wheels on the tractor or a single per axle? The single wheel may appear to be more wasteful but is actually a more fuel efficient alternative to running the dual wheels on the tractor. It also reduces weight by eliminating an extra rim & bead lock ring.

If you do not run these trucks at their full 80K pound capasity all the time I always thought a bounce house like inflatable bag that could fill the gap between the cab and trailer would help improve air flow over and around the trailer, using hot air from the exhaust to keep it inflated with a small exhaust vent for when the bag is compressed on tight truck turns.

More to come ...

[SmartTrucker]

The trucks are long haul so yes they are all outfitted with sleeper births.

We run the northwest states and have a licensed GVW of 98,000lbs stateside. But you are correct weight is almost always an issue. You are also correct about the wasted energy. There's a lot of excess heat from the engines and especially the exhaust. As well running the engine fan to keep things cool while pulling those hills is a drain on our horsepower. If we could collect energy from other sources otherwise wasted to power things like a guys fridge or that engine fan I'd think that would help but those are overhauls well beyond my means unless they are selling systems like that as kits.

We've thought about Tautliner trailers before but the cost outlay is much higher and they don't work with a lot of unload and reload situations that load with an overhead crane etc.

Also are trailers are flatdecks. If they were Vans I'd have some ideas far beyond what I've seen anywhere so far hehe. It would deal with the gap between the tractor and trailer

[trikkonceptz]

Check out this site .. Home

They have an a/c heater system for your trucks that is independant of the engine and electric loads, thereby letting you sit overnight without idling the trucks. That alone could save you big bucks at the pumps.

[IndyIan]

I guess aerodynamics is still a big issue with trucks, but how about the single wide tire vs, dual skinny tires? I don't know if the single tire has lower rolling resistance or not but it might be something to look into.

Also something simple would be coasting downhills in neutral, and pulse and glide should have good benefits for such heavy vehicles.

Can trucks maintain air pressure at idle in a long panic stop?

[johnmyster]

Wheelskirts

[SmartTrucker]

Originally Posted by IndyIan

I guess aerodynamics is still a big issue with trucks, but how about the single wide tire vs, dual skinny tires? I don't know if the single tire has lower rolling resistance or not but it might be something to look into.

Also something simple would be coasting downhills in neutral, and pulse and glide should have good benefits for such heavy vehicles.

Can trucks maintain air pressure at idle in a long panic stop?

The super singles you are referring to have been tested and are a fuel & weight savings but unfortunately they don't have the same weight acceptances where we travel so we can't use them on our units at this point.

The sad thing is there's improvements that can be made but many are cut off from us due to the rate at which government moves on things

[FunkSkunk]

Just a few links I found for you two to chew on....

Freight Wing Incorporated - 6% fuel savings with our Aerodynamic Trailer Skirt, The Belly Fairing and Gap Fairing.
Aerodynamic improvements & flow control boost fuel efficiency in heavy trucks
Aerodynamic Truck Trailer Cuts Fuel And Emissions By Up To 15 Percent
Increase diesel truck fuel economy and mileage efficiency with AirWedge

Also think about gap reducers between cab and trailer and Boat tail the trailer.

HTH

[FunkSkunk]

here's another link --> SmartWay Tractors and Trailers - Partners - SmartWay Transport Program - EPA

[Johnny Mullet]

What kind of trucks? Kenworth W900 or something more aero like the Kenworth T2000?