Bad, And I Mean Bad, MPG

[tmtott@aol.com]

I have a 2003 National Dolphin LX, on the Workhorse, I did the Banks upgrade, it helped the driveability, downshifted faster so that the rpm's didn't get so high. it didn't really help the mileage. My name is Tim so I had to have MORE POWER, my coach would stop at 76 MPH. I got in touch with Brazelsrv.com 1-877-786-1576. I got an upgraded computer for the engine and alsom traded out the one for the allison. I love it. The transmission upgrade gives you the downgrade braking like the 2005 and on trannies have. We towed our S-10 Blazer to the Carolina's and back to Shreveport getting 6.8 MPG average, running the generator about half of the time.

Have you had the brake recalls done on your coach? If not check into it.

[Rosco]

On Our last trip after new Transmission we got 7.14 MPG an I was happy will try Iso Heat for next run only to Salem OR about 200 round trip, we run a 2004 workhorse with 98,500 now

We will make the run to Gillette thru Jackson Hole lots of Climbs this June, See you all there

[mcgsecrest]

Here's the scoop, Continued... getting the wheel weights of you toad is part of the tire pressure maint. checks. On Toads and any other Vehicle, the proper pressure is on a sticker, in your door jamb.

SURPRISE !, the factory has hurriedly weighed that car at manufacture... NEVER USE THE TIRE SIDEWALL MAX Pressure. The "must have junk" you cram in the toad adds weight but endeavor to zero in on a proper pressure for your car tires too.

As for the ISO-Heat, I have a 60 gallon GAS tank... I pop 3 bottles in ANYTIME to treat 60g... full would be good. Yes, you've heard it's a winter water drier but it has beneficial additives for 10%ethanol we have in the NE.

Kevin510, What is your year & Engine Size... I missed that.

Gary

[J79Engine]

I have a 2005 38 foot SunVoyager 8.1 GM workhorse with Alison trans. I reduced my speed to 60 max and get around 6 MPG while towing a 2012 GMCTerrain AWD weight is at 3200.

I did have a engine check light problem but after having it checked twice we all came to the conclusion my gasoline octane was too low. I was using regular gas but when I started using 92 octane the light never came back on, so think when towing the toad the 92 octane needs to be used and so I just always fill it with 92-93 gas.

I try to watch the speed and keep it below 60, I may try keeping it down at 55 and see if it produces better gas mileage now that we are stepping into the young senior years...LOL

The problem I have at the moment is it will not start often on the normal battery but kick in the house battery switch and it starts fine. I think I need to check voltage drop on the lead from the battery to the starter which will probably show I need a new lead to correct the problem. All batteries were replaced last year so I know it is not the battery.

Trials & tribulations of RV life! Eventually we will retire for the second time and we can enjoy the sights of the USA...is that not what we served 17 years overseas for in a 22 year USAF career!

[mcgsecrest]

J79engine... Try getting a FREE battery load test at Advance or Autozone for a base line test on the chassis battery. Follow up with a good quality Hydrometer. I KNOW... messy but they don't lie.

My Rig's Converter/ Inverter DOESN'T charge the chassis battery while maintaining the house batteries very well. My workhorse only charges the chassis battery from the Engine Alternator. You drive a few hours yet there is lots of parasatic drain 24-7, 365. I augment the system with an inexpensive charger/ maintainer for the chassis battery.

Caution, Don't overcharge.

Good luck

Gary

[bathurstj]

Motorhomers typically drive way too fast. I drive 60MPH, and eveyone passes me including tag-a-longs, fivers, and the like. Slow down, what's the hurry? My rig weighs 29,925 and I tow a mini cooper, and I get 9 MPG.

Years ago there were some independent studies done that showed that it takes 10% more fuel to raise your speed from 60 to 65. You are not driving something that is aerodynamically designed. Even with no headwind at all, you are pushing a lot of air in front of you.

You can add all sorts of junk to that engine, and I doubt you'll see any appreciable increase in MPG.

A few years ago, I drove from home in IL to MI to attend a rally. I reset the GPS before I left. I did the computations when I arrived, and discovered that driving 55 MPH all the way, I got 10.2 MPG and I calculated that I arrived 47 minutes after I would have had I drove 60. Do the math.

[Kevin510]

I have a 2003 National Dolphin LX, on the Workhorse, I did the Banks upgrade, it helped the driveability, downshifted faster so that the rpm's didn't get so high. it didn't really help the mileage. My name is Tim so I had to have MORE POWER, my coach would stop at 76 MPH. I got in touch with Brazelsrv.com 1-877-786-1576. I got an upgraded computer for the engine and alsom traded out the one for the allison. I love it. The transmission upgrade gives you the downgrade braking like the 2005 and on trannies have. We towed our S-10 Blazer to the Carolina's and back to Shreveport getting 6.8 MPG average, running the generator about half of the time.

Have you had the brake recalls done on your coach? If not check into it.

So if I am understanding you. Your upgraded trans automatically downshifts when slowing down or going down a grade? My trans does this as well. Does that mean that the computer in mine has been upgraded?

[AlexBall]

Hi Kevin,
Just a couple of points. I run a 04 w22 with the 8.1 & a 5 speed. pushing a triple e 36' 21000 lbs & towing a 2010 equinox awd.
I run at 60mph on cruse rpm at 2050. This week on NV hwy #93 on the long flat desert the dash showed 9.9 ave mpg.

I think you should check the hitch on the rig it is likely rated at 5000 max. The Insurance co. will jump all over this if you have an incident.

I would also suggest you use a top grade synthetic oil, as this engine runs very hot.( My preference is amzoil).

Workhorse has an add on air intake to push more Air past the manafolds to help with the cooling.

Alex Ball

[belsen]

So if I am understanding you. Your upgraded trans automatically downshifts when slowing down or going down a grade? My trans does this as well. Does that mean that the computer in mine has been upgraded?

Kevin, this is what he is talking about.........Grade Brake for Workhorse 2001 -2004

[mcgsecrest]

Alex Ball et al........... I have a 2450 Landau 8.1

I suggested to my mechanic I'd cover the grille to stop frigid air thru firewall bulkhead.

ABSOLUTELY NOT... as you said, this engine runs very hot routinely.

I got a Workhorse recall, 2004, Vortec 8.1 Fuel Rail, pressure regulator steel hairpin BREAKS & SPRAYS FUEL.

If this applies to any of you, hope this helps.

Gary

[wolfe10]

To follow up on Gary's post, any restriction to the air flow through the radiator will cause the fan clutch to engage more. And, that takes a lot of HP and fuel to run it.

[mcgsecrest]

Thanks Wolfe10... totally understood. My reply was to Alex Ball who said 8.1s run hot. I encountered VERY cold weather while driving in an ice storm. The front of my Landau is there only to hold the windshield... It does nothing for creature warmth. Teasing my mechanic I suggested cardboard "BRA" for the front of my Rig, he nearly fainted.

Yes indeed mechanical fans....As the post back a few "The Roar".

You're Right Sir.

Gary

[autzig]

I have a 2003 Monaco with a Workhorse chassis. It generally goes into OD at about 56 or 57 MPH. And that's where I usually drive it. Accordingly to the trip computer average MPG, on level ground here in the Sacramento Valley, I usually get 9 to 10 mpg. I rarely run over 60 unless it's downhill. My speedometer is within 1 mph by GPS. I have checked the trip computer several times at fill up and it seems pretty close. I too have drooled on the Banks system, but I don't see much of a mpg gain, not enough to justify the cost. As long as you can keep it in OD (usually about 50 or so depending on throttle position), the slower you go, the better the mileage. I also have a towed, but it's pretty light, about 2050 lbs.<br /><br />Al Utzig

[JOHNDONNA]

Both Cummins and Cat have interesting papers on fuel economy. The Cummins Site has a white paper covering all aspects of fuel economy, This is diesel information, but you will be surprised at the number of factors covered. Copy and paste the following link

http://cumminsengines.com/assets/pdf/MPG_Secrets_Whitepaper.pdf

John

[mcgsecrest]

Hey, JohnDonna, Please check the Cummins link... I can't open it. Thanks Gary

[wolfe10]

Here is Caterpillar Corporation's "Understanding Coach/RV Performance" document:http://forum.dieselrvclub.org/index.php/topic,6594.0.html

Just click on the link at the bottom of the post to pull up the PDF file.

Here is Cummins's document: http://cumminsengines.com/uploads/docs/cummins_secrets_of_better_fuel_economy.pdf

[wildebill308]

Brett, thanks for the links.

[wildebill308]

I am not sure I understand what you mean by a "payback down the road" I was referring to the Banks system and its cost to benefit ratio. Not the cost of the rig its self.

I don’t get to worried about “payback” when doing anything with a motor home. I would probably be sitting in my back yard doing a “staycation” rather than traveling.

Lets look at some alternative things you can do to improve your mileage. The reason I recommend Banks is it is a complete package that is engineered to work together. You can do about the same on your own by improving exhaust flow. You can add good set of headers Gibson makes some.

http://www.gibsonexhaust.com/motorhome/

These long tube headers will improve torque.

http://www.dougthorleyheaders.com/products/productID/1082

Add in a couple of free flowing mufflers and you will see an improvement in overall performance.

I would also add a cold air inlet system to get more cold air to your intake. I do not like the K&N style of air cleaners I have seen test where they flow more air but also more dirt.

Bill

[McCleery]

As long as we are talking about mileage - what do folks have to say about Ford V-10 on a 450 Chassis and the Ford auto tranny? I get around 9 MPH at 60-62 MPH towing a Dodge Dakota 2 door with a topper. Just curious - it's not real good but I don't consider it too bad either. Thanks, Geary

[dickandlois]

Hi Geary ! Welcome to FMCA.

Well if your getting 9 MPG I think you should just keep smiling as the white lines disappear under the coach.

Rich.

[dbelanger]

Hi everyone.

I finally got to take my rig out on a pretty long trip and was surprised by the mpg that I got. It is a 2003 Newmar Scottsdale on a Workhorse chassis. It is 37' 9" and weighs about 19,500 lbs. with us in it. We pulled our Jeep Commander on a 2,200-mile trip a few weeks ago.

When we left Amarillo, we had to fight a terrible head and cross wind (about 50 mph). We drove east to OKC trying to drive anywhere from 55 to 70 mph to find that "sweet spot" where the coach wouldn't have to downshift to fight the wind and slight hills. We fueled in OKC and got about 4.6 mpg. I wasn't totally surprised by this due to the wind. We continued our travels east to Nashville, Tn. I drove most of the trip at 65 mph but did try to slow down for a few tanks but it didn't seem to help. The best I could get was 5.5 mpg.

The best I have ever gotten was 6.9 from Amarillo to Okmulgee, OK. driving about 62 to 65 mph. It has a brand-new air filter.

The exhaust seems to be okay and not clogged or anything like that. No foul smell like a clogged catalytic converter. There is no check engine light and the engine seems to run great. It has plenty of power, never gets hot or misses. About the only thing it has ever done is have a low idle at times but that seems to have cleared up recently. Is this normal for a rig of this size? Is there anything I can do to get some better mpg?

I am not expecting a lot, but I think that 5.5 is a bit low.

Any and all thought are welcome.

Thanks

I have a 2007 Fleetwood Pace Arrow on a Ford Chasis. All I get is an average 6.8 (all fuel used since I bought it new) But I tow a Ford Focus that weighs only 2500 lbs. Your coach's combined vehicle weight is somewhere in the neighborhood of 26,000 lbs. The Jeep takes you close or over that. I had a 2000 Holiday Rambler on a Ford Chasis that could get 10.5 with no tow.

[wildebill308]

As long as we are talking about mileage - what do folks have to say about Ford V-10 on a 450 Chassis and the Ford auto tranny? I get around 9 MPH at 60-62 MPH towing a Dodge Dakota 2 door with a topper. Just curious - it's not real good but I don't consider it too bad either. Thanks, Geary

There are people who would be extremely happy with that mileage. I just got back from filling up after a short trip to Bandera Texas. Had strong head and side winds both ways with lots of construction areas. I averaged 7.608 towing my Civic. I would like to go somewhere where it wasen't up hill both wayes with strong head winds.

Bill

[mcgsecrest]

Wildebill308 & All,

Glad folks are hitting the roads!

Reminder: The Air Cleaner. Mine is in a wheel well with simple snaps to open, clean, change & snap shut... Ha, maybe when I was 40!

Be Safe,

Gary

[ticat900]

Thanks for the replies everyone. I do use the cruise until it comes time to climb a hill. I also figure the weight of my toad has a lot more to do with it. I looked it up and the Jeep weighs about 5200 lbs. I had been considering selling it to either go to a diesel or something smaller but I guess I will keep it for a while longer and try some different speeds. I am also going to try and pull my parents CRV on the next trip and see if that makes a difference. It weighs about 2000lbs. less than the jeep. I am also going to check the odometer the next time I get it out.

What do you guys think about changing the plugs? I doubt that they have ever been changed and I have about 55k miles on them. Any other ideas are welcome. Does anyone know if they make a tuner for this chassis?

A 38 foot gasser pulling a 5+K jeep at 65MPH will never ever get better than 6.5MPG combined driving. Flat highway no hills shall garner about 1MPG better.

[bsinmich]

You are very close to my '03 Mountain Aire with the same drive train. My toad limit is 4000#. I would suggest you download the brochure, from Newmar, that will give a lot of the details on your MH.

If you actually go and weigh it I think you will find you have a lot heavier MH than you are guessing. If I drive carefully I can get 8+ mpg but with a headwind I will get around 7. The less you touch that accelerator the better the mileage. The 8.1 seems to take a lot more fuel as the RPM increases. On your instrument panel you can set the mpg to instant. That is always interesting to see what you are getting under each driving condition.