Cruisers Forum
Main Forum => General Discussion => Topic started by: BuffaloRose on September 26, 2014, 07:33:29 pm
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I'm sure this topic has been discussed at length, but just feel frustrated. We traded a 30 foot class A for our PC and hoped we would gain at least a little better gas mileage. Both vehicles have the same Ford e350. Our class A often got 9 mpgs towing our Ford Escape. We typically don't go over 65 and are mindful of weight loads. Have now driven our PC in various conditions, towing and not towing. Our best mileage todate is 8.5 mpg. How is it that the same motor on a smaller, more aerodynamic vehicle can't beat a 30 foot long shoebox driven much the same but with a heavier load? Very disappointing. pyho
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Every once in a while I will read a post like yours. I can't explain why a few people get poor mileage. The only thing I can suggest is to do what you can with driving habits and vehicle maintenance to see if you can influence it for the better.
Do keep in-mind that some people will claim great gas mileage. I for example could say that our rig gets between 13 & 14 mpg on the open road. Though true in one sense, it would be very misleading to proclaim. If we travel on a level interstate highway with no winds and nobody near us (mainly night driving) at a steady 55 mph, our ScanGauge-II will be reading about those figures. But keeping track of miles driven and gallons of fuel purchased throughout the duration of a vacation, we calculate trip averages of 9.5 mpg when towing our Jeep Liberty, and 10.5 mpg when not. Also remember that we live in the Chicago area so much of our driving is done in the Great Plains where better mileage is achieved.
One other influence is generator usage. Because it uses the fuel from the main fuel tank, the more you run the generator, the lower your gas mileage will calculate.
Oh yes, if your rig is built on an E450, most people seem to drop about 1 mpg due to the change in gear ratio in the rear axle differential.
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Thanks Ron. Can always count on you to help out on the forum. I guess maintenance means filters and oil, etc. We just changed the oil and only ran the genie for 20 - 30 minutes for maintenance. Husband says he hasn't checked the air filter, so will do that before leaving for Acadia NP this coming Sunday. I'm guessing with traffic congestion up the east coast things will not improve. We do have the e350 with a slide. Any other thoughts will be appreciated.
Rose & Earl tymote
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I guess maintenance means filters and oil, etc. We just changed the oil and only ran the genie for 20 - 30 minutes for maintenance. Husband says he hasn't checked the air filter, so will do that before leaving for Acadia NP this coming Sunday. I'm guessing with traffic congestion up the east coast things will not improve. We do have the e350 with a slide. Any other thoughts will be appreciated.
Rose & Earl tymote
You are very welcome!
Yep, oil & filters, proper tire inflation, etc.
I have been using 5W-20 full synthetic motor oil since the second oil change. Around here where we live, Quaker State full synthetic can be purchased occasionally on sale with a rebate for $1.99 per quart at Menards. That brings the cost down to regular oil. I would like to think that full synthetic oil helps a little in fuel economy, but I can't say for certain. It does provide me with a little more peace of mind when engine braking in the mountains, watching the tachometer get near that red mark.
Full synthetic gear oil is available for the rear axle differential. That too might help mpg a bit. I would not change that oil until it's time, but am planning to use full synthetic then.
I do wonder if all the mounted RV accessories, roof storage, and things some people hang on their rigs, has a measurable influence on fuel economy. General "weight" is always a factor too. Don't bring along heavy things that you find yourself never using......but keep the spare tire and jack. :)
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Rose and Earl
Ron presents some very good points.
We had a 2008 2350 with slide on an E350 chassis and over the first 10,000 miles of usage we averaged 9.98 miles per gallon.
Some of the things we found that help the mileage:
1. Maintain good tire pressure. Good is hard to define. The tires need to be inflated enough to carry the load but not so much as to cause a rough ride and excessive tire wear.
2. A clean air filter helps . I added a K&N air filter primarily to increase time between filter changes.
3. Starting and stopping in heavy traffic or at stop lights destroys the mileage.
4. When towing I usually maintain about 60-62 MPH.
5. Hills will also greatly affect mileage. I found that if I am able to keep my speed in the 60+ range I can climb a lot of hills without having the transmission down shift.
On a separate issue the Ford V10 used in some if not all Class A's is slightly different than the V10 used in an E350 Class C. The Class A would have a 3 valve configuration and the Class C would have a 2 value. I do not know if this was the case in your previous Class A.
Barry
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Thanks Barry Sue. I think Earl will replace the air filter before we head out. Always try to watch our speed. Sure would be nice to get 10 mpg, even 9 :'(
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BuffaloRose
I am posting my log file so that you can see the MPG we were maintaining over the past few years. We have a 2008 PC2350 with a ladder, luggage rack and solar panel mounted. We also travel with a Stowway box on the hitch.
The trip mileages reflect both back roads and highway driving.
Bill G
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I failed to mention ...it is an Excel File.
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Got it Bill. You have meticulous records there. Thanks for sharing. At a glance there have been times you got some great mpg. Outstanding! We generally only check our mileage occasionally at the beginning of purchase of a new/different unit to get an idea of how we are doing. We have only filled the PC 4 times since purchasing in February. My husband was saying maybe we should start keeping a log (that means me heartshower). I'm beginning to think "why worry, we love our PC and traveling to new places no matter what the mileage." I think we will just be cognizant of things we can manage as noted by you folks and then enjoy the trips!
Thanks again.
Rose and Earl
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Keeping Logs goes with the fact that I had to do it everyday for 38 years as a truck driver. And, it allows me to go back over the records to see the overall performance of my PC.
I will add that at the beginning the mileage was between 8 to 9 mpg. on the first trip from Mass. To Florida. After we had a front end alignment, and engine timing adjusted we were able to improve the mpg . The maiden voyage just after delivery from the factory.
Bill G. :-D. :)
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Old habits can be good habits as your records indicate :). We just had a front end alignment so only about 30 miles driven on this tank after having that done. Plan to change air filter prior to leaving for Acadia NP on Sunday. Might look at timing adjustment when we return. Good info. Maybe some tweaking will help a bit.
Thanks,
Rose & Earl
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Perfect timing for Acadia NP .....Great foliage and no crowds
:-D
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I use the Android app called Fuelio to keep track of the mileage on our 2 vehicles. Works great. Don't know if there is an Iphone version
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Good topic,,, so of course have to add my 2cents haha
First,,, I try and maintain the Beast to good standards,, do not worry to much unless the MPG goes crazy,, Usually in the 9..... range,,, do know that wind is big booger also
Question,, especially for some of you guys that do tons of records.
Most of us buy the cheapest gas we can find,,, I am a big Flying J fan..... I do know that the cheaper brands of gas do not have the same additives/detergents in them from the more expensive brands,, Shell/Texaco etc,,,,, I do a fill up about every 4/5 time with better brand gas or add some additives to the tank......... could buying the cheaper gas make a difference.??? Since it would be cheaper to buy the additives over 10 to 15 cents a gallon,,,, just curious
sparky
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Sparky, You bring up a very good topic. Does the brand and octane of gas influence fuel economy? I have an opinion, but will wait a bit before sharing it.
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Theoretically as long as it is the octane it is designed for, using a higher octane would actually lower your mpg.
Brand has no effect, all comes out of a limited number of refineries. I see all the brands using the same refinery.
What has the biggest effect is % of alcohol they put in the fuel. If you can get 100% gasoline you will improve your mpg by as much as 10%.
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I think your response is wrong,,, yes they do use the same refineries,, but I do know that the major companies do add detergents and other additives to their product.... as far as Octane yes there is a difference not sure if that has an effect,,, and who wants to pay 20 cents plus a gallon for 88 when 86 works find,,, unless you get about 2/3 mpg
sparky
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It's a recorded fact that using non major brands of gas, any octane, causes problems in the long run with intake valve deposits. The fix is to run every 4 or 5 tanks, a major brand, ie BP, Shell, etc in the medium or high octane variety, (full tank), to help clean those deposits off of the valves. Any more often with the higher octane is a waste of $$$.
Some folks use gas additives all the time, like some use diesel additives on every tank. Dunno about that because I've never done it....
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A app I use on my phone is MyCarProjects.com. I find it very easy to enter the info for as many vehicles as you want. It also keeps track of maintenance items etc. Most of all it's easy to use. While your standing at the pump you just enter the info on your smart phone. It connects to a website that you can access from a home or office desktop and that way print out graphs and all sorts of info on your vehicle. You don't have to use it every time you fill up which was a problem I had with other gas mileage trackers. It estimates what your total mileage is based on your use and every couple of months I go to the web site and just update that. I do try to use it every time as I'm self employed and my work mileage is deductible. It's has been a real benefit to my tax filing. I got audited once and when the IRS agent questioned my car deductions I pulled out my records from MyCarProjects and he closed the audit right then.
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Here is what I had always understood about gasoline.
Which octane to use? - The octane stated in your vehicle owner's manual.
- Consistently using a higher octane than recommended, will form carbon build-up (black soot) on and around the valves and valve seats. continued build-up will eventually prevent the valves from completely closing during the critical compression stage of the engine.
- Using of a lower than recommended octane will cause the rattling noise we are familiar with. With continued use, this could cause damage to the valves.
Higher octane fuel burns a tad bit slower than lower octane fuel. Hotter running, high compression performance engines require the fuel to burn at that slightly slower rate to prevent pre-detonation, that rattling noise.
When traveling through high altitude communities, you'll see lower rated octane fuel than sold everywhere else. The lower octane helps to compensate for the thinner air at those higher elevations. So if your owners manual says to use regular 87 octane gasoline, feel free to use 85 octane in the mountains.
Which brand to buy? - Buy from the newest and busiest gas station to assure the cleanest underground gas station tanks and the freshest fuel.
Brand names have their own formulations for detergents and other fuel additives. Keep in mind that all fuel sold in the USA meets the government standards for detergents and general formulation for use in fuel injected engines. Using the same brand consistently "might" benefit your engine electronic and emission systems to calibrate and stay there from one tank to the next. I really don't know if vehicles are sensitive to such variations. You might benefit slightly sticking to one brand, or maybe no benefit at all.
Adding Your Own Fuel Additives
I would not bother with any product sold off the shelf for today's vehicles. I even question fuel stabilizers for off season storage for a 6 month period. Just store your RV with a full tank of gas to reduce the open space in the tank to minimize condensation potential. Additives are generally not worth the expense for any benefit received. There are special products only the professionals have access to. That is not what I am talking about. One of the silliest things to add to your fuel these days is gasoline anti-freeze. It is basically a bottle of alcohol. Since todays fuels are at least 10% alcohol based called ethanol, you already have gallons of the stuff in your tank. Another 8 ounces won't matter.
One liquid treatment I bought many years ago for cleaning my valves was a product called D-Karbonizer. It was not sold in stores, an expensive mail order item. I owned a Pontiac Fiero-GT that had suffered from a pinging engine when using the proper low octane gas. It was the byproduct from over-use of premium gasoline which resulted in carbon soot contaminated valves. After the unique process of treating the engine by sucking the liquid through a vacuum port with a fast idle, the product actually eliminated the pinging and I was able to return to the specified 87 octane after the treatment. I assume enough soot on the valves and valve seats was removed to allow for a proper valve-to-seat seal.
I am no expert on this subject matter. This is only what I had gathered over the years.
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Holy cow, Ron, if I could have sent 5 helpful stars your way I would have! Great info, thanks for posting it. Especially helpful to me was answering the question of whether I should have/could have used the 85 Octane found in the mountain regions. Thanks everyone for this thread.
:)
Carol
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Oops. Got kicked off by weak wifi in the campground and I accidentally posted my update to my mileage saga under a new subject. Please check gas mileage update for my thanks for the help here. Something clearly worked!
Rose&Earl
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What octane does the Ford V10 in these RVs call for?
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2012 2910 here..7.5 to8 mpg....no matter what I do!
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Generally get about 8-9 give or take. Have squeezed out 10, flat terrain, not towing on our 3100.
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The brand nor octane matters. But they put 10% alcohol in most gasoline. This will drop your mileage by at least 0.5 mpg.
I had a E350 once that got 5 mpg, took it to Ford. They found that the air ducting to the fuel injection system was not installed correctly and air was leaking. They fixed under warranty and mileage jumped to 10 mpg.
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On the first 2552 on the E-450 chassis made for us, we were averaging 5.3 mpg, took it to Ford and they said there is nothing wrong with it. That is why we do not have it anymore. There was something wrong with that engine as almost all the driving was on mostly flat terrain between 55 and 60 mph. Sure wish Ford could have found something fixable because we liked that coach.
Bob