Gasoline vs. diesel

Hearing of the problem encountered when a caller put 6 gal. of diesel in a gasoline-powered car, I was reminded of my experience a few years back when I rented a VW Beetle TDI in Belgium. At that time VW wasn’t exporting diesel-powered New Beetles to the U.S., so it didn’t occur to me that it wouldn’t take gas. It performed less than optimally after filling it when half empty and after the second filling it stopped altogether, fortunately not far from a VW dealership. The employee drained the gas tank and towed me to a fuel station where I filled it with diesel and went on my merry way, $150 poorer but much wiser. Diesel engines may be tougher than gas engines, but your suggestion should be more than adequate. I wonder if anyone who mistakenly put diesel in a gas-powered car has just drained the diesel/gas mix out and filled it with gasoline without all the cleansing of lines, etc.

That’s why filler nozzles and fuel receptacles are different diameters.


It’s actually generally worse to put gasoline into a diesel than vice versa, partly because a diesel is more likely to run on a gas/diesel mix. Diesels rely on the lubricity of the fuel itself to lubricate many (expensive) components, so even though they’ll run on largish gasoline concentrations, it can cause some seriously expensive damage. In general, running diesel in a gas engine might foul up some fuel system components, but won’t cause any serious long-term damage.

Judging by how many “gas in a diesel rental car” stories I’ve heard from American tourists in Europe, if I lived there I probably wouldn’t want to buy a used diesel rental car!

That’s why filler nozzles and fuel receptacles are different diameters.

It was that way at one time. You could not put a diesel nozzle in a gasoline cars filler pipe, but today the size of the car’s filler and the fuel station nozzle sizes are all over the place.

Sorry Joe, but you can not put a diesel fuel nozzle in a gasoline powered car…All gasoline powered cars sold in the United States have had nozzle restrictors since 1975…But it’s quite easy to put gasoline in a Diesel…

I respect your expertise, but the VW technician didn’t show any concern. I have a diesel electric generator, to which I’ve added regular oil (incorrectly), and about which technicians have told me - not to worry - diesel engines are “tanks.” After my misadventure in the low countries, I monitored my mileage with proper diesel fuel and got excellent mileage for a couple thousand kilometers afterwards.

Diesels have high-pressure injection pumps that are lubricated by the fuel… At some point of gasoline dilution, these expensive pumps will fail…Also, gasoline tends to detonate when injected into a Diesel engine. This detonation can quickly damage the engine. You got lucky…