Was speaking to a work collegue and he uses the following for his Toyota HiLux:

Kerosene
Engine Oil.

He mixes 250 ml of oil for every 25 litres of kerosene and it runs fine, he's not had any problems and has been doing this for years. The oil being mixed thoroughly into the kero. for about 5 minutes before adding it to the tank.

Interestingly, he ended up being 'dipped' by the custom's people during a routine check and nothing showed up on it.

I think it works out to about half the price of deisel fuel at the moment if using Kerosene...

Diesel engines, however, are remarkably tolerant of fuel formulations and can run on just about any low volatility oil based fuel, but of course that doesn't mean they should or that it is even legal (tax wise) or beneficial to do so. While the engines themselves (pistons and valves) are more or less indifferent to fuel types, the emissions and injection controls on modern clean diesel engines would likely be damaged by using any fuel other than ULSD or B5.

Taken from here

A few friends mix their diesel with jet fuel 50/50 they have plenty of surplus left over which cant be used in aircraft after it reach a certain date but it fine for automotive. I would still be nervous around what it does to the injection pump but they had no problems

Like most fuel they degrade after a certain time, if not filtered and tested. But most big fuel companies prefer to have the fuel issued, used regular because of commercial business practice and loss of earning mainly. That why there was a small campaign for people to only buy small amounts of fuel say the minimum issued of 2 ltrs. This can put pressure on the oil company to drop the prices because they don't like having blocking.