Class 8 Trucks - Page 2 - Fuel Economy, Hypermiling, EcoModding News and Forum

Clev · 08-29-2008, 07:22 PM

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 · 08-29-2008, 07:31 PM

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 · 08-29-2008, 07:35 PM

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 · 08-29-2008, 07:43 PM

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 · 08-29-2008, 08:13 PM

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 · 08-29-2008, 09:07 PM

Wheelskirts

SmartTrucker · 08-29-2008, 09:46 PM

Quote:

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