If you take the oil, which I recommend, be sure to filter if well. The oil probably has been in the tank for years and could be full of water and rust. Don't everyone jump up and say that Diesel tanks don't rust because the Diesel is oil. The inside top of the tank rusts because the tank 'breaths' the moist air. This moisture and rust will fall to the bottom of the tank and make a very nasty sludge.

Secondly, unless, as was mentioned, this sale is some sort of sting operation, your chances of getting stopped and your tank dipped are about those of the US finding Bin Laden any time soon. But, the fact remains that in spite of what 'mplafleur' says the simple act of having un-taxed fuel in your tank is illegal, regardless of how or why it got there. This is like someone putting an open can of beer in your car. If you get stopped in Texas you can be given a ticket under the open container law even though the can is not yours. You are the captin of the ship so to speak and are responsible for what goes on on aboard.

If you haven't paid Federal and local road tax on that fuel, and more importantly can prove it, you are violating the law. This also holds true for all those of us using bio-Diesel and used veg. oil. In essence you are using the state and federal highways w/o paying for that use and these guys (the Feds)can, and rightly should, get a bit irate about this.

By the same token, I have been driving for over 45 years and have never ever been stopped and had my tank dipped. I would also doubt that anyone on this board or anyone that they know has ever had their tank dipped. So, in essence, go for it.