Community Forums

MrTrouble · 05-25-2016, 10:57 AM

Hello all,

Has anyone tried putting together a fuel pre-heater to increase fuel economy on your coach? I have a 36' coach and it is a long run from the fuel tank to the fuel rail. I was considering creating a pre-heater in the engine area for the fuel to get a more efficient combustion and, hopefully, boost my fuel economy a few mpg.

Anyone?

Thanks in advance,

Juan

epj · 05-25-2016, 11:29 AM

I've spent a lot of time and effort on various gasoline powered vehicles trying to keep the fuel from heating. If heated too much, you will create lots of headaches. I can't really imagine you would see any improvement in economy. Certainly not several mpg, and probably not even several tenth of a mpg. Just my two cents worth.

LETMGROW · 05-25-2016, 11:55 AM

Quote:

Originally Posted by MrTrouble

Hello all,

Has anyone tried putting together a fuel pre-heater to increase fuel economy on your coach? I have a 36' coach and it is a long run from the fuel tank to the fuel rail. I was considering creating a pre-heater in the engine area for the fuel to get a more efficient combustion and, hopefully, boost my fuel economy a few mpg.

Anyone?

Thanks in advance,

Juan

You are thinking backward here. Cold fuel is more dense. Hence the fuel is more efficient. That is why many race cars have "cool cans" packed with ice with the fuel line running through it.
I wouldn't suggest throwing ice cubes in the gas tank though. LOL
Lynn

powercat_ras · 05-25-2016, 01:59 PM

Quote:

Originally Posted by MrTrouble

Hello all,

Has anyone tried putting together a fuel pre-heater to increase fuel economy on your coach? I have a 36' coach and it is a long run from the fuel tank to the fuel rail. I was considering creating a pre-heater in the engine area for the fuel to get a more efficient combustion and, hopefully, boost my fuel economy a few mpg.

Anyone?

Thanks in advance,

Juan

Colder air and fuel input conditions produce a very small but measurable increase in engine power (otherwise intercoolers would not be installed on turbo engines.)

About the only thing I would make sure of is that your air intake is located to get air that is not being heated by the engine.

Nick-B · 05-26-2016, 03:00 PM

Hi Juan,

I think we all appreciate someone thinking outside the box for a solution to a problem we all suffer from - namely, poor fuel economy. Some pretty innovative approaches have been tried over the years and nobody has yet made any significant improvements in getting better mileage from a Class A gas chassis. There are simply too many obstacles that are part of the basic coach design that prevent us from achieving any positive results. Large frontal area and the basic aerodynamics of a brick, plus HUGE amounts of weight to move down the road. Modifications which work well on cars and light trucks simply do not translate into increased MPG on a big motorhome.

The best you can do is keep the engine in good working order and use a light foot on the gas pedal. Just fill the tank and enjoy the ride!

MrTrouble · 05-31-2016, 06:39 AM

Quote:

Originally Posted by Nick-B

Hi Juan,

I think we all appreciate someone thinking outside the box for a solution to a problem we all suffer from - namely, poor fuel economy. Some pretty innovative approaches have been tried over the years and nobody has yet made any significant improvements in getting better mileage from a Class A gas chassis. There are simply too many obstacles that are part of the basic coach design that prevent us from achieving any positive results. Large frontal area and the basic aerodynamics of a brick, plus HUGE amounts of weight to move down the road. Modifications which work well on cars and light trucks simply do not translate into increased MPG on a big motorhome.

The best you can do is keep the engine in good working order and use a light foot on the gas pedal. Just fill the tank and enjoy the ride!

Thanks.... Yeah, trying to think of all the things I've done in the past on cars and bikes. I know that the sheer size, girth and aeros are the killing points for the fuel economy. I just want the make the engine as efficient as I possibly can and maybe get a touch more out of it.

skypilot_1 · 05-31-2016, 07:10 AM

On big block Olds I've used dry ice box and water injection. But heatin fuel, not so much.

twinboat · 05-31-2016, 07:26 AM

Just watching

rambler62 · 05-31-2016, 06:07 PM

I can not believe this. Everyone is trying to get cold air and fuel into the engine and you want to heat it? Just think about it. Why are there so many cold air intake systems out there and why don't you ever run a fuel line near anything hot.

bluepill · 05-31-2016, 06:22 PM

Why you don't want hot fuel:

https://en.wikipedia.org/wiki/Vapor_lock

Best MPG = Well-tuned and maintained engine, and a light right foot.

Ethanol-free gasoline has more energy content. If you can find it for the same price as the corny stuff, go for it.

Ray,IN · 05-31-2016, 09:00 PM

Pre-heating gasoline was the basis for the 200 MPG carburetor. http://www.allpar.com/old/200-mpg-carburetor.html

We all know liquid gasoline will not burn/explode, only vapor will burn/explode. An internal combustion engine utilizes a controlled explosion of gasoline vapor.

skypilot_1 · 06-01-2016, 09:41 PM

Quote:

Originally Posted by Ray,IN

Pre-heating gasoline was the basis for the 200 MPG carburetor. The 200 Mile-per-Gallon Carburetor: The Story of the California Carburetor

We all know liquid gasoline will not burn/explode, only vapor will burn/explode. An internal combustion engine utilizes a controlled explosion of gasoline vapor.

Don't think they seen any Holley double pumpers in 1902.

Coma · 06-02-2016, 07:32 AM

Back when gasoline engine were used on heavy trucks the trick was to turn on the windshield wipers, when they stopped it was time to shift. Why did that work, the windshield wipers were vacuum powered.

I would put a vacuum gauge on and drive by that, striving to keep the highest vacuum for a given power requirement. I think you will be surprised by how little a throttle movement will affect a large change in vacuum.

IMHO

TQ60 · 06-02-2016, 07:50 AM

If it has a fuel rail it has a computer that will modify lots of things to keep the oxygen sensor voltage in range.

Engine is closed loop so modify this and computer changes something else.

Reason for the tuner buisness...

Things can be modified but everything comes with a cost.

Modifying the air path is most effective meaning better exhaust and possibly intake.