Anyone know about diesel fuel quality, additives and their potential affect on the emissions test?
Last time I had my LR Defender TD5 through the emissions test it seemed to struggle, needed revving to the full and holding it there to get the numbers down. There was a leaking manifold at the time, where it mates with the turbo, which may gave been affecting it, I dunno.
Anyway, it’s (over)due again, and I just spotted elsewhere some mentions of fuel additives, both in what you get out of the pump and stuff you can add to the tank. Seems like one of those topics that there’s as much BS out there as there is any useful info.
So, is there any difference between diesel fuel from various Swiss suppliers?
Is it different from what I normally get over the French border (closer and cheaper).
Do any of them, and/or the ‘premium’ diesel fuels give lower emissions?
Same for the additives you can buy and put through the tank yourself.
Are they really worthwhile for any other reason?
When was the last time it had a serious service? Did you have the leaking manifold fixed?
My feeling is that instead of worrying about fuel quality and additives, read the owners manual and do as recommended. Perhaps before testing, take it out on the autobahn and drive it in reduced gear to high rev the motor. That is the best way to clean out a motor.
Yes, it was fixed, yes, it’s up to date on proper servicing, yes it gets driven enthusiastically enough to ‘clean it out’ on a regular basis.
The questions about the fuel are not to address any problem I may or may not have. As already mentioned there’s quite a lot to be found on the internet, but mostly it’s vague and talks about making an engine run better, smoother, longer, etc. etc. and also mostly does not include any real reference criteria.
I just want to understand, is there actually a link, either directly or indirectly, between fuel quality or additives and the results I’d get in the emissions test, and if so which fuel or additive is better?
Not just normal driving but constant almost red lining the engine for about 15 minutes may help. Also replacing the air filter can’t hurt.
Otherwise try tanking at BP or Shell. They have all the additives your car may need.
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Thanks, but the problem with those links is it’s the manufacturers, making sweeping yet still somehow vague claims. Like, obviously they just want you to buy the more expensive stuff all the time.
My question remains, not that I expect anyone to be able to answer it, given that the internet has failed to do so with any real believability,
Does just using these additives in a single tankful reduce the emissions? If it needs some time to ‘clean’ before any improvements then how long, how many tankfuls?
The price difference is huge, with a litre of French B7 diesel coming in at around chf1.55 compared with chf1.96 for the Swiss premium diesel, so I need to know if it’s justfied.