Mileage loss when towing

[GORDON HUMMEL]

I am 2700 miles into my spring trip & towing a car for the first time. I expected to notice some loss in mileage because of the added weight, but I was surprised at the results! The Newell weights 41250 & the car 3000 lbs, a 7% increase. My mileage previously had been 6.7 MPG over the last 30,000 miles. Towing, it has gone down to 6.0, a 10% loss.
For this trip I reduced my speed from 67 MPH, 1800 RPM to 62 MPH, 1700 RPM.
Also just install H rated steer tires inflated to 120 PSI vs the old tires @ 105 PSI. Figured this might provide some less rolling resistance ?
I try to drive as much as possible using the boost gauge as an indicator. In the past, not towing, I would run < 7 lbs of boost at 67 MPH. I am now over 7 @ 62MPH.
My question is am I expecting too much?
Am I running below the sweet spot in the fuel curve? Can't find one for this engine!
If I was towing 30,000 lbs, would my mileage be 2MPG ?

Any thoughts

[tuga]

Gordon,

My experience has been you lose about 1/2 mile per gallon when towing a vehicle.

If you are getting 6 mpg with an 8V92 towing a vehicle you are doing great!

Don't worry - be happy! Life is great when you're in a Newell.

[jack14r]

I agree that towing reduces the MPG by a lot more than we would expect,I always loose at least .7-1 mpg.It must be a result of drag rather than weight,also I can tow a stacker trailer that weighs 17,000 LBS and it is a little worse than a 6,000 LB truck.

[chockwald]

Pulling our enclosed trailer with the T-Bird in it for the first time this past October when we met Forest and Cindy Olivier (Folivier) in Santa Fe we got around 8mpg....trailer plus car around 7,000 lbs. Keep in mind that our coach is only 36' long and weighs only 29,000 lbs. so we get decent mileage even without the enclosed trailer....probably 8.5 depending on terrain. Like Tuga says..."Life is great when you're in a Newell"

[tuga]

I wonder what the difference in mpg would be comparing a 35' Newell and a 45' Newell with the same engine, say an 8V92? Pulling a tow car and then another test not pulling a tow car.

The mass would be the same going down the road; only difference would be the weight.

Has anyone ever done this comparison?

[tuga]

I met a guy last week who said that a DD mechanic told him that if he drilled out the diesel return fuel line CONNECTION he could increase his mileage. So he did it and he claims that he gets 8.2 miles per gallon towing a toad.

He has a series 60 in a Prevost H3 Vantare' 45'. That is driving 65 mph!

Any thoughts?

[express1]

Got a drill!

[Richard and Rhonda]

Ok, here is the theory.

If you drill out the return restriction then your fuel pump actually circulates more fuel back to the tank, and in theory you will be sending cooler fuel to the injectors. Cooler fuel or cooler air means more power. That the good news. Now for the bad. I happen to know first hand where this very fitting is located on a Series 60 and what you have to do to get to it.

It is installed on the rear of the head. You have to remove the bedroom hatch, and be prepared to loosen and tighten three diesel fuel fittings to get it loose. They have to be done in a particular order because the fitting is L shaped and the whole L must be unthreaded from the head. You have fun with that.

There are all kinds of guys out there who are hot rodding DD engines. If you google around you will find enough info to make your head hurt.

I don't fret about mileage. It is a minuscule cost of owning any coach when you total depreciation and maintenance.

That pedal on the right. Stand on it.

[Richard and Rhonda]

If you want to read a whole lot of engine stuff, this is the DD forum that I visit.

http://www.dieselenginetrader.com/diesel_talk/categories.cfm?catid=9

[larryweikart]

I just had a presentation given me by the distributor of a lp injection system for diesel engines. They claim 3 more mpg on a series 60, 100hp increase in power, cleaner emissions and a 50 cents per gallon, alternative fuel, tax CREDIT! I talked to Coker Fuel, in Sebring, Fl. about their experience on the trucks they use with this system and they attest to the claims made by the Dist. as being true. Evidently the Europeans have been using this system for quite some time. I use our coach in our business and travel approx 15000 mi per yr with a 24,000 lb trailer in tow. At $1300 installed, my payback would not take long. I find it very interesting and am seeking any additional info that may be helpful.

[express1]

I could see this happen!

[prairieschooner]

just for giggles look at this, this is one of those engines that were burried;
http://www.motortrend.com/classic/features/c12_0603_1964_chrysler_turbine_car/specifications.html

[tuga]

I just had a presentation given me by the distributor of a lp injection system for diesel engines. They claim 3 more mpg on a series 60, 100hp increase in power, cleaner emissions and a 50 cents per gallon, alternative fuel, tax CREDIT! I talked to Coker Fuel, in Sebring, Fl. about their experience on the trucks they use with this system and they attest to the claims made by the Dist. as being true. Evidently the Europeans have been using this system for quite some time. I use our coach in our business and travel approx 15000 mi per yr with a 24,000 lb trailer in tow. At $1300 installed, my payback would not take long. I find it very interesting and am seeking any additional info that may be helpful.

Larry,

Is LP as accessible as diesel fuel for the average motorhomer?

Do most truck stops sell LP?

I remember a few years back that my cousin purchased a Gulf Stream motorhome that had a LP generator. The MH had a diesel engine. My cousin said he had a tough time actually buying LP when he wanted it; either the LP tank was padlocked or the LP service guy was at lunch or something like that.

Does anyone have any first hand experience with purchasing LP?

Are 18 wheelers converting to LP?

[chockwald]

Hey Tuga, I have an LP (propane) generator. Have never had trouble getting LP. Most Flying J's (Pilot) sell propane. Don't know if most truck stops sell it, but many Flying J's offer it at their RV islands where you can fuel up, dump your tanks, add water to your fresh water tank, and take on propane without moving and inch.

[rheavn]

My 1984 Pace Arrow had a propane generator. My experience was much closer to what Tuga's cousin experienced than Clarke's. I said never again for LP. It is also the reason that when I purchased my Country Coach & Newell I wanted an all electric coach.
As for Flying J's getting a 36' coach with a tow vehicle up to their propane tank in the curb lane of their rv fuel area would be much less challenging than performing the same manuever with a 45' coach with a tow vehicle. Again my comment is from first hand experience. No LP for me.

[larryweikart]

I have to add lp in our trailer every trip and have no problem finding a suitable location for filling. I have a very large tank on the coach which is used for our 2 furnace's. They would just tap into this supply for the injection system which requires only 3% lp injection. The system they use is also low maintenance since it operates with air pressure and has no computer chips.

[chockwald]

Steve: You are absolutely right. Maneuvering a 45' coach through their islands would be difficult at best. A couple of years ago I pulled into the Kingman, AZ Flying J for diesel and propane, which was just a straight in situation, but to depart the island I had a hard right to make with the trailer. Had to go in the store and get the owners of two cars parked in front of the store to move their cars. That was tight. We've got a 60 gallon lpg tank so don't have to fill it up often. Ironically, lpg costs way less than diesel right now. Used to be the other way around. I can get lpg locally for $2.99/gallon, and diesel for $4.25/gallon. When gas/diesel is cheaper than lpg I tote along a 1,000 watt Honda generator to run the coach systems (except the microwave and A/C). Fortunately we haven't had to fill up with propane often using the coach once a month (maybe twice per year), but now that we are fulltiming we'll find out what our new frequency will be.

[tuga]

Thanks Clarke, Steve, and Larry good posts all, but does anyone know of any 18 wheelers that are converting to LP or CNG? Question: What is the difference between LP & CNG?

To my way of thinking when the big boys start converting, things will improve greatly! A LP or CNG pump on the diesel islands at major truck stops would make a believer out of me!

I have tried to use the RV lanes at some Flying Js and Pilots; you always take a chance of being blocked in by a car or truck that is inside the store. I always use the truck lanes for that reason.

[larryweikart]

I also use the truck lanes at any fueling stop and I definitely agree that the chances of filling lp at the Flying J is difficult and almost impossible with my trailer in tow. I have traveled the same routes for so long that I know where I can fill easily.

[chockwald]

If I'm only getting diesel, then I prefer the truck lanes....pumps must faster there, but if I am taking on propane, and dumping, then how long it takes to fill the diesel tank doesn't matter.

[jack14r]

I got to go back to post # 8 and have someone explain how drilling a larger return will increase MPG in a big way,I am not doubting this I just want to understand.I have actually heard this from a friend that was at Prevost Nashville last year.

[tuga]

I got to go back to post # 8 and have someone explain how drilling a larger return will increase MPG in a big way,I am not doubting this I just want to understand.I have actually heard this from a friend that was at Prevost Nashville last year.

Jack,

I talked to Larry Byrd; he has an H3-45' Vantare'. He gave me the name and phone number of the mechanic that did his. If you would like me to PM you the guy's name and phone, I'll be glad to send it to you.

Larry is very happy with the results! I think I am going to talk to the guy and see what he says.

[prairieschooner]

Clark,
That is allot of gas, it explains everything