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Disappointing gas mileage

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keelhauler

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Re: Disappointing gas mileage
« Reply #15 on: September 30, 2014, 10:56:48 am »
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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Sparky

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Re: Disappointing gas mileage
« Reply #16 on: October 01, 2014, 08:36:44 am »
 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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bobojay

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Re: Disappointing gas mileage
« Reply #17 on: October 01, 2014, 01:40:12 pm »
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....
Bob & Sharon
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Future: 2100 special, 2350, ?? on a hopefully Ford Transit 350 or 450

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NHWanderlust

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Re: Disappointing gas mileage
« Reply #18 on: October 07, 2014, 12:06:57 pm »
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.
Richard & Jackie Whitney
Lee, New Hampshire

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Ron Dittmer

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Re: Disappointing gas mileage
« Reply #19 on: October 07, 2014, 04:24:03 pm »
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.
« Last Edit: October 08, 2014, 02:05:02 pm by ron.dittmer »
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Carol

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Re: Disappointing gas mileage
« Reply #20 on: October 07, 2014, 05:13:59 pm »
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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BuffaloRose

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Re: Disappointing gas mileage
« Reply #21 on: October 07, 2014, 06:19:16 pm »
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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NHWanderlust

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Re: Disappointing gas mileage
« Reply #22 on: October 08, 2014, 01:20:16 pm »
What octane does the Ford V10 in these RVs call for?
Richard & Jackie Whitney
Lee, New Hampshire

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Lieutenant

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Re: Disappointing gas mileage
« Reply #23 on: December 22, 2014, 09:10:29 pm »
2012 2910 here..7.5 to8 mpg....no matter what I do!

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GoPhoenix

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Re: Disappointing gas mileage
« Reply #24 on: December 22, 2014, 09:15:14 pm »
Generally get about 8-9 give or take.  Have squeezed out 10, flat terrain, not towing on our 3100.
I remember very few of the things that Iíve spent money to buy, but I remember all of the places that Iíve spent money to see.

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keelhauler

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Re: Disappointing gas mileage
« Reply #25 on: December 31, 2014, 07:57:55 pm »
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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gl1500

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Re: Disappointing gas mileage
« Reply #26 on: January 03, 2015, 12:57:19 pm »
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