penitent diesel idiot
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Joined: Jan 2007
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From: Cheshire, UK
penitent diesel idiot
i have come to confess my sins.
put diesel in my c2 last week (F*****g WHAT?!!). luckily realised my mistake before starting the engine. fortunately only put 10 litres in an empy tank (coz didn't have much cash on me!). my specialist advised i could dilute it with unleaded and should be ok - and so it has proved, runs completely normally as far as i can tell. am topping up with unleaded every 100 miles as also advised, but i have another question - how long do i have to do the topping up thing before it's safe to run the tank low again?
am i embarrassed or what!
cheers, andrew.
put diesel in my c2 last week (F*****g WHAT?!!). luckily realised my mistake before starting the engine. fortunately only put 10 litres in an empy tank (coz didn't have much cash on me!). my specialist advised i could dilute it with unleaded and should be ok - and so it has proved, runs completely normally as far as i can tell. am topping up with unleaded every 100 miles as also advised, but i have another question - how long do i have to do the topping up thing before it's safe to run the tank low again?
am i embarrassed or what!
cheers, andrew.
Race Car
Joined: Aug 2001
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From: London, UK
To be honest, I would have been tempted to have the car's tank siphoned at the start but as it runs 'normally' I would be tempted to fill up as much gasoline as possible as soon as possible - i.e. dilute themixture as much and as soon as possible just in case.......but I have no actual scentific reason for doing this - just instinct....
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From: Cheshire, UK
To be honest, I would have been tempted to have the car's tank siphoned at the start but as it runs 'normally' I would be tempted to fill up as much gasoline as possible as soon as possible - i.e. dilute themixture as much and as soon as possible just in case.......but I have no actual scentific reason for doing this - just instinct....
trouble is, i don't know how long it going to take to get rid of the original 10 litres diesel!
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From: Atlanta
I would worry more about how long my rubber parts (hoses, seals in injectors and pumps) were exposed to the diesel fuel. Even diesels of the vintage of our 964s developed leaks when the oil companies changed the process to remove the sulphur from diesel.
My $0.02 says drive to empty ASAP. Otherwise, get the test hose from your mechanic's flow-test kit, and fit it to the test port on the injection manifold (one on each side and easy to get to). The 964 fuel pump will drain a full tank in 15 minutes or so. Given cost of fuel these days, you should have no problem locating someone willing to take it off your hands - perhaps someone with a diesel, which would not be harmed as long as 20:1 dilution with fresh fuel is maintained.
My $0.02 says drive to empty ASAP. Otherwise, get the test hose from your mechanic's flow-test kit, and fit it to the test port on the injection manifold (one on each side and easy to get to). The 964 fuel pump will drain a full tank in 15 minutes or so. Given cost of fuel these days, you should have no problem locating someone willing to take it off your hands - perhaps someone with a diesel, which would not be harmed as long as 20:1 dilution with fresh fuel is maintained.
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From: Virginia
I guess dilution really IS the solution for pollution. I don't have the answer, but it has to have something to do with how well the fuels mix once you are on the road and they start sloshing. While they may settle out, I would think that once you get moving in city traffic they would mix pretty well.
Let's do some math as it makes my back of the napkin calculations seem more legitimate:
65 liter tank.
10 liters #2 Diesel oil
55 liters gasoline
So after the first fill up if they are mixed well, every liter is about 1/5 diesel and 4/5 gas.
Lets say you did 100 miles and used 20 liters of fuel mix. That would mean you burned: 1/5 of 20 = 4 liters of diesel. Then you filled up. Now you have:
6 liters of diesel
59 liters of gas
so about 1/10 diesel to gas
Assuming a good mix again, 100 miles would mean you burned 2 more liters leaving you with 4 liters of diesel and a mix of 1/15.
The reason it feels never ending is that, well, it won't ever end.
However if you put more than 100 miles on it between fill ups you will get rid of the diesel faster. What you have left is pretty diluted already, so it should not hurt.
Let's do some math as it makes my back of the napkin calculations seem more legitimate:
65 liter tank.
10 liters #2 Diesel oil
55 liters gasoline
So after the first fill up if they are mixed well, every liter is about 1/5 diesel and 4/5 gas.
Lets say you did 100 miles and used 20 liters of fuel mix. That would mean you burned: 1/5 of 20 = 4 liters of diesel. Then you filled up. Now you have:
6 liters of diesel
59 liters of gas
so about 1/10 diesel to gas
Assuming a good mix again, 100 miles would mean you burned 2 more liters leaving you with 4 liters of diesel and a mix of 1/15.
The reason it feels never ending is that, well, it won't ever end.
However if you put more than 100 miles on it between fill ups you will get rid of the diesel faster. What you have left is pretty diluted already, so it should not hurt.
Nordschleife Master
Joined: Dec 2006
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From: S.E. VA
...apparently, diesel is not very miscible with unleaded, so sits at the bottom of the tank when unleaded is added. as you run the engine, unleaded is drawn into the engine, along with trace amounts of diesel that are mixed in. topping up every 100 miles or so means you are gradually getting rid of the diesel with every litre of unleaded burned.
Guess you learn somethin' new every day...
To answer your original question, IF it does mix somewhat well, and you had, say, 1 gallon of the original diesel remaining for that first gas-fill, then you'd have a 4.9/95.1% cocktail of diesel/gas. Second fill up, that's down to 0.2/99.8%. Third fill-up, 0.0006/99.9994%. Or so I figure. It's a Quick dilution. (Mathematically, it's an exponential drop.) Still, that's hundreds of miles of engine run on Not righteous fuel. (Bad juju, brother.)
I like Springer's vision of using fuel pump to evacuate. Pay some wage in the short run, saves peace of mind in the long run.
If it's NOT miscible, then you're in for flush sequence math that's beyond my meager chemistry knowledge.
Here's one good thing to keep in mind: predictably, you aren't the first person to have done this, and if there was some commonly lurid outcome, then it'd be a LOT more prevalently posted around here. So, I figure absent those tales, that after a few reasonable steps are taken, your carerra will be none the worse for wear.
-Lonnie
Last edited by elbeee964; Feb 19, 2008 at 08:34 AM.
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Joined: Jan 2007
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From: Cheshire, UK
MisterRisky - like your regression analysis! from what i understand though, mixing is slight no matter how aggressive my driving may be (though the mechanic is probably guessing as much as we are!)
Lonnie & springer3 - now there seems to be more uncertainty about what might be going on in the tank, a fuel drain is looking very attractive as you suggest. i did do a search, and like you say there is no other report of this happening, so probably not much to worry about. My mechanic did mention this happens more often than you'd think - maybe i should have stayed sheepishly quiet about it like everybdy else has...
cheers guys, andrew.
Lonnie & springer3 - now there seems to be more uncertainty about what might be going on in the tank, a fuel drain is looking very attractive as you suggest. i did do a search, and like you say there is no other report of this happening, so probably not much to worry about. My mechanic did mention this happens more often than you'd think - maybe i should have stayed sheepishly quiet about it like everybdy else has...
cheers guys, andrew.
Drifting
Joined: Mar 2004
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From: behind the Corn Curtain
Hi Andrew,
As I doubted the thought that diesel and unleaded were not miscible, and having both on the farm, I just worked up a 50/50 blend, lightly swirled and observed. As expected, they are miscible. Both unleaded and diesel are refined from the same barrel of oil. Your car runs fine because it is fine.
Best,
As I doubted the thought that diesel and unleaded were not miscible, and having both on the farm, I just worked up a 50/50 blend, lightly swirled and observed. As expected, they are miscible. Both unleaded and diesel are refined from the same barrel of oil. Your car runs fine because it is fine.
Best,
