I'ts an old story. A bloke is throwing balls of grass into the canal, and when asked why, he says it keeps the sharks away. "But there aren't any sharks here." says a passer by. "Proves it woks then." says the bloke.
That's the trouble with preventative measures. You never know if they work until you stop taking them.
Scare stories about diesel bug have got a lot of us paying good money for fuel additives in case they work. About a year ago I stopped using Fuel Set and swapped to Marine 16 on the recommendation of RCR backed by Tony Brooks. As well as combating diesel bug, it also claims to counteract the recent reduction in sulphur content in diesel. Us with older engines need sulphur as an injector lubricant and to protect seals. No, not seals, seals. Anyway Marine 16 is not cheap, I reckon it adds up to 4p per litre extra on your fuel bill.
Then yesterday, for some reason I cannot now recall, I was reading the Marine16 blurb on the net. I noticed that they also claim an improvement in fuel consumption. Hang on a minute, when I last bought diesel I recorded my engine hours as usual and noticed that over the last year Herbie’s fuel consumption had dropped significantly. By about 7 or 8% I reckon. Actually, a bit better even than that because we have been using the Eberspacher a bit. That means a saving of roughly £25 a year. About enough to pay for the bottles of Marine 16 :-)
Can this really be down to Marine 16?
The only other reason I can think of is that we may have been driving more economically. This is entirely possible. We do seem to be cruising at slightly lower revs these days and we've also been doing some heavily locked trips where the engine spends longer at idle.
On the balance of probabilities, I'd plump for the better driving Of course it might be a bit of both. I shall never know unless I stop using the additive. Then I might find out the hard way that it works!
Oh I just thought of another reason. I may have got my figures wrong. Surely not! Next time I'm on the boat I'll double check.
Has anyone else used Marine 16 and found an improvement in fuel consumption? I’d love to know.