What degree of gasoline/diesel contamination is permissible?

[Copperhead]

Well then I may be incorrect. I have never seen a manual state 30% gasoline. Of course, #1 or kerosene, yes. Either way, given the properties of gasoline, I wouldn't even consider it except only in the most extreme of circumstances. And that is where it is at anyway. If one is getting the right fuel and properly maintaining their fuel system, the need for gas in diesel would not ever exist.

But if one has the fortitude to try it, let us in on how a 10%, 20%, or 30% blend works out in one of the newer diesels. Given that in older diesels, a 10% might not cause a problem, I cannot see how running 30% gasoline would not cause significant damage even in older diesels. To even attempt that with todays diesels, get ready to break out your wallet.

Could you please post a scan of the page in your manual that states John Deere has no problem using 30% gasoline in diesel? Curious minds would like to know. I have no problem being proven wrong.

 

[buickanddeere]

What exactly makes gasoline blowup or ruin diesels.
The operator's manual went with the skid steer when Father retired from bailing round bales of hay.

 

[Deere Dude]

What exactly makes gasoline blowup or ruin diesels.
The operator's manual went with the skid steer when Father retired from bailing round bales of hay.

What was the model number? Maybe the manual can be found on line. I am really curious now.

 

[Copperhead]

What exactly makes gasoline blowup or ruin diesels.
The operator's manual went with the skid steer when Father retired from bailing round bales of hay.

Gasoline is a lot more volatile than diesel. Diesel has a higher flash point. The compression and heat generation of the compression stroke of a diesel, and gasoline can do some interesting things like blowing holes in pistons and other neat stuff. And gasoline in diesel in a significant ratio can ruin the fuel system, as diesel fuel systems rely on a certain level of lubricity in the fuel. Gasoline washes the lubricity from the pump and injectors to the point of the equivalent of using sandpaper in these components. In older diesels, one could maybe not do any damage with up to 10% gasoline, but it is still a bad thing for any diesel. To run 30%, man, that is going to ruin a diesel motor in quick order. The uncontrolled detonation of a significant percentage of gasoline in diesel fuel will really reek havoc on wrist pins, rods, etc, and destroy them pretty quickly.

There has been some testing done with using a multi fuel mix of gasoline and diesel recently, but we are talking about separate fuel tanks and computer controlled dual injection setups that are very precisely timed to prevent any issues. And the results are very promising. Significant power while offering 10-20% better economy compared to diesel alone.

 

[buickanddeere]

Operation at -40F is different than operating in the south at 100+ F . Iirc VW also suggested a percentage of gasoline during extreme cold.
Gasoline while it has a higher ignition temperature than diesel or kerosene . The advantage is that gasoline with vapourize and form a combustionable air/fuel mixture . At temperatures and conditions that diesel stays in non combustionable liquid form.
The gasoline also dilutes the concentration of paraffin .
Where gasoline in a diesel is a problem occurs when Bubba fills an empty diesel tank with gasoline making for a 75-95% ratio of gasoline to diesel. Particularly in the summer.

 

[Retiredguy2]

Interesting to read how this thread has morphed into a rather different subject, but I appreciate all the opinions. Copperhead, where did you learn of the testing on the multi fuel mix of gasoline and diesel fuel? Can you provide a link? We may all learn something from it.

 

[Streetcar]

I have Also read of the testing on diesels with mixed fuels. I think it was Volvo doing the testing on engines for over the road trucks. I do not have link. Article was in magazine for construction equipment

 

[Copperhead]

Regarding testing being done on bi fuel (gas and diesel), here ya go. It does require separate tanks for each fuel and the mix is computer controlled....

http://www.sciencedaily.com/releases/2009/08/090803132737.htm

Gasoline-diesel 'cocktail': A potent recipe for cleaner, more efficient engines

 

[ModMech]

With an older non-electronically controlled engine (pump-line-nozzle) type, 1% is not a problem in the sort term, but continued operation at 1% WILL reduce component life.

For YEARS I mixed a small amount of gasoline with #2D in my car to prevent gelling, we lived in MN and it was the ONLY way I could be sure to make it to work at 3am with temps hovering in the -30*F range. That car was hyper sensitive to fuel restriction and the pump could not pull fuel thru the filter with even the slightest restriction. No commercial products worked and at that time, no station sold a reliable mix anywhere near my normal driving routes.

This was back when "fuel" was about $1.25/gallon and I would literally use $0.25 of unleaded then fill with diesel, so 0.2 gallons gas with 10 of diesel. I put over 100k on that car and it was never a problem.

I would NOT suggest anyone else do this, I am a fully trained and certified diesel tech specializing in fuel systems and performance diagnostics, You mileage WILL vary.

 

[clemsonfor]

no problem at all. If you worry put some of what ever your putting in there slosh it around and pour it out and refill, it will further dilute it. But seriously its not necessary. It wont hurt.