Does diesel really need oil?
QA fellow boater told us we should be putting a measure of two-stroke oil in with the diesel, which would lubricate/protect the injectors and pump. Would that be correct because we have never heard of the idea before? MAGGIE ALLEN, via email
ATONY REPLIES… It will do no harm other than just possibly make a bit more exhaust smoke and might increase the rate at which carbon builds up in the engine and exhaust, but this would be at a very slow rate.
The specification for diesel fuel (and what we buy is now road diesel with red dye added but may have no bio-content) will show a minimum lubricity specification so, in my view, it’s just another old wives’ tale.
It might have originated from the time Lister was saying that you could run their engines on paraffin as long as you added lubricating oil to it. It may have been from an incomplete understanding of fuel specifications so that when low sulphur fuel became mandatory, some thought the sulphur acted as a lubricant and needed replacing with something.
To further put your mind to rest, think about the combined harvesters and tractors that farming contractors use. They run on the same red diesel and clock up a massive number of hours per year, all without two-stroke oil in the fuel. If this still worries you, you could use something like Redex diesel additive or, better still, something that fights diesel bug.