Adding Diesel to gasoline

[tasdrouille]

Originally Posted by tjts1

You don't need to be insulting just because you think you're right. And yes, you are advocating for it.

You need to clearly specify:
There is NO evidence that there is any FE benefit here
This DOESN'T work on EFI engines which makes up 99% of the vehicles on the road today
It HAS NOT been tested on emissions controlled vehicles.
There are UNKNOWN long term consequences of putting diesel fuel into a gasoline engine in any proportion.

Well, it's true that your post that prompted his comment didn't have much meat to it. When you state your opinion it's good practice to back it up. So it's a good thing you replied with additional info.

That being said, there is anecdotal evidence that there is a FE benefit. I have not seen evidence it doesn't work on EFI engines. If I put 1% diesel in my Elantra I'm pretty sure it'll be business as usual. But at what ratio will I start having trouble that I don't know.

[gone-ot]

...does anybody else see any similarities here between these:

(a) aiding and abetting at a drag race.

(b) aiding and abetting exceeding emission regulations.

...or:

(c) aiding and abetting a suicide.

(d) aiding and abetting putting diesel in a gasoline engine.

...shall I continue?

[Christ]

Noone here has had a chance to prove yet (through data gathering and proper testing procedures) that there is, has, or can be an improvement. It takes time, man.. you don't get results right away, or the test wasn't worth it.

Personally, right now, I have no valid way of testing the theory. I do know for a fact that I've run diesel through gasoline engines, and they were undamaged by it. You haven't proven otherwise, although you make claims that gasoline engines are in direct danger of contact from diesel fuels.

[RH77]

Fifth Gear did a test where they switched fuels on diesel and gasoline test vehicles a year or 2 ago, and ran them around their test track. I can't find the vid anywhere.

Essentially both test vehicles operated somewhat normally...

RH77

EDIT: Should we try this on a small-scale first, like a lawn mower? Winter is setting in here so it just sits in the garage. Sounds like fun!

[Christ]

Originally Posted by RH77

Fifth Gear did a test where they switched fuels on diesel and gasoline test vehicles a year or 2 ago, and ran them around their test track. I can't find the vid anywhere.

Essentially both test vehicles operated somewhat normally...

RH77

EDIT: Should we try this on a small-scale first, like a lawn mower? Winter is setting in here so it just sits in the garage. Sounds like fun!

You could try it on a smaller scale, but there are directions available for converting B&S (older) motors to run on kerosene, as I noted above. I'll see about copyright info and see if I can scan the page, provided I still have access to the original manual.

I'll also try to see if I can find it online somewhere. I believe the end result is increased power on gasoline, and about 25% less power on kerosene, but ~25% increased fuel economy. (lbs/hp-hr)

[tasdrouille]

If I were to try it in my Elantra I'd probably fill with high octane gasoline to start with, since diesel will bring the octane level of the whole blend down. Also, I'd want IAT pretty high, to minimize the unburnt diesel as much as possible. Finally, that shouldn't be a problem for hypermilers, but I'd generally keep revs pretty low.

[lindsayjim]

Originally Posted by tjts1

You don't need to be insulting just because you think you're right. And yes, you are advocating for it.

You need to clearly specify:
There is NO evidence that there is any FE benefit here
This DOESN'T work on EFI engines which makes up 99% of the vehicles on the road today
It HAS NOT been tested on emissions controlled vehicles.
There are UNKNOWN long term consequences of putting diesel fuel into a gasoline engine in any proportion.

It would be helpful if you read my previous posts with comprehension in order to avoid misrepresenting what I've provided here.

1. I've posted the change in FE which I am experiencing.
2. The vehicle I'm testing this blend on is a spark ignition, EFI engine.
3. My vehicle has fully functional emission controls. It passes testing.
4. Long term consequences are unknown. They could be good or bad. It is my opinion they will be good in my vehicle under my conditions of use. Your vehicle, your variables and your results may not be the same. Be thoughtful and careful.

I'm driving a 1 ton work van 20K a year in Alaska. Saving $30/K keeps $600 a year in my pocket. That's enough to make the exploration attractive to me. You can learn from what I've experienced to date.

You can benefit from what I've documented. You may choose to avoid the risks. It's a free country, place your bets and take your chances.

[RH77]

Well-put, lindsayjim.

We have to remind ourselves why we are here at EM: not to find the same old information, but to engage in an exchange of new ideas. In this case, it appears to be a tested idea.

Before throwing something out, I say we let Science do the work for us, instead of saying "maybe" or "doesn't sound right".

RH77

[darcane]

Originally Posted by tjts1

Does adding diesel fuel to gasoline in any proportion increase or decrease the overall octane rating for the fuel?

It decreases it. Dramatically.

Diesel has an octane rating around 20 or so IIRC. So, the more diesel fuel you mix in with your gas, the more the octane rating drops.

Even though a diesel engine and a gasoline engine are similar, there are significant differences between the engine cycles that allow them to work with their respective fuels.

A Diesel cycle only adds the fuel AFTER the compression stroke. At this point it ignites as it is injected.

An Otto cycle (gasoline engine) uses a mixed fuel/air charge that is ignited by the spark plugs. If your fuel is prone to autoignition, it begins burning early, possibly even during the compression stroke. However, since it's a well mixed charge, it detonates rather than burns evenly. This can be very damaging to your engine.

In small percentages, I can see diesel simply lowering the octane rating and the EFI pulling back the timing enough to compensate. Mix it in too high of a percentage and you will get detonation or the engine won't run at all. This is a very risky way to try to improve efficiency and I wouldn't recommend it to anyone.

Mike

[gone-ot]

...octane is a figure of merit of the gasolines' resistance to detonation during compression buildup...diesel doesn't have this problem.

...cetane is a figure of merit of diesels' ignition delay, ie: burning-rate under compression.