Luckily ruining a car is a mistake you only make once!

If OP hadn't cranked it yet, they can siphon the gas back out, it'll take some time and a little work, but at least the long term effects will be cheaper. Wasting a tank of gas is much better than buying a new truck.

My question is how you didn't notice it was diesel. My dad has a diesel truck and it is extremely loud and sounds nothing like a gas truck.

I did not know there was difference in the sounds, thanks for the advice

Good luck, OP! Sounds like you'll need it. It's an easy mistake to make if you're not very familiar with cars.

Think of it this way op. Bonding time with your brother while you guys siphon his truck out

New diesels are much quieter but they do still sound different

And they have a green cap and have a sticker that states: "diesel only".

#48 not all of them do. Mine has a silver cap.

Luckily if you drain the tank and refill with diesel it sometimes works out with little damage.

Or illiterate.

I don't understand why they didn't make them physically incompatible with normal gas? I mean they could just give the hoses a different shape, like those baby toys with square, circle and triangle. Or other neat tricks.

Diesel fill holes are generally bigger, to accommodate for the larger nozzles at diesel pumps. When OP said too late that to me sounds like they had started or even driven the vehicle and won't be as easy as draining the gas and changing some filters. Especially if the vehicle is a newer one, the modern injectors don't like the mixture of gas and diesel.

I'm just wondering how OP didn't know based on how you start a diesel. I'm speaking from my own experience, but don't you have to turn the key halfway and let the glow plugs warm up? It's cold outside, I would imagine it having a slight issue starting up. Though, excuse my ignorance if I'm incorrect.

88, you are actually very right. In the cold, quickly cranking a diesel may cause a no-start condition.

#88 Yeah in my dad's truck you turn the key almost all the way but then you have to wait until a little red light turns off and then it is okay to start it. In my experience, his truck starts up much different than my gas car. I'm not sure how you could mix the two up

In the newer dieseles engines you don't have to wait for the glow plug to heat. If it is old enough that you would have to let the glow plugs warm up, since it the engine was already hot there would be almost not noticeble waiting time.

#98, I realize that after OP put in gas in it would start up without much trouble, but what I meant was when they first got in the truck they had to have had a bit of trouble. Possibly after they got done with whatever they were doing they could've had trouble too. I wasn't talking specifically after putting in gas.

There's never a bad time to learn to siphon gasoline lol hopefully they can learn quick.

Haha right

I think OP's brother started it and found out..

I agree, that is a big oops. That can ruin your car. On the bright side, you can still fix it if you haven't started it yet.

If the engine is fried, it's not even worth repairing. Diesel engines are very pricey. Once you get into the man hours and the cost of the engine, you'd be better off buying a new car.

I'd rather have a low tank of gas then a ruined engine needing a full replacement.

Why do you let him drive it if he doesn't ever fill it up? I'd be fine with a couple times but if it was always and he doesn't fill it even though you ask, he shouldn't be allowed to use your car. Otherwise he's just learning that he can use it without having to fill it.