Ds5 fuel consumption

[Peter.N.]

It depends primarily on where and how you drive. I can get 70 mpg on the motorway from my C5 X7 estate, but then I am an old man and drive like one.

Peter

[Michel]

Over the years I've used many "premium" fuels and come to the conclusion they're all b0ll0cks. Not a single one has made any appreciable difference.

[mickthemaverick]

Over the years I've used many "premium" fuels and come to the conclusion they're all b*****ks. Not a single one has made any appreciable difference.

All I would say is that the difference is most noticeable in terms of engine condition and oil cleanliness but it only happens gradually over a long period of consistent use. Using the odd tank here and there may well help with injector cleaning etc. as Marc finds but the real benefits only come to light with consistent use for 5000 miles plus.!

[Michel]

Over the years I've used many "premium" fuels and come to the conclusion they're all b*****ks. Not a single one has made any appreciable difference.

All I would say is that the difference is most noticeable in terms of engine condition and oil cleanliness but it only happens gradually over a long period of consistent use. Using the odd tank here and there may well help with injector cleaning etc. as Marc finds but the real benefits only come to light with consistent use for 5000 miles plus.!

But how do we know? Do you strip your motors down after so long check?

It even states in my Yamaha MT-09 owners manual *not* to use premium fuels as the engine isn't mapped for them.

[mickthemaverick]

But how do we know? Do you strip your motors down after so long check?

It even states in my Yamaha MT-09 owners manual *not* to use premium fuels as the engine isn't mapped for them.

I only know from the oil colour which definitely is much cleaner at oil changes than it used to be on leaded 4* and from the general lack of any form of engine faults occurring. I have never suffered valve issues or bigend wear for example in any of the cars, including a few very high mileage ones, since I have been using it. It is only personal experience which leads me to my conclusion and I would say that while the mpg is definitely improved, the mpp (miles per pound ) may be slightly reduced but I view that as the cost of better performance and smoother running. I'm certainly happy with it.

As regards your Yamaha then I would always follow the manufacturers advice and accept what they say about mapping. My RF900 runs very well on it as does the Deauville and they may have similar notes in the manuals which I have never read but I will have a look when I next go down to my man-cave

[Michel]

I only know from the oil colour which definitely is much cleaner at oil changes than it used to be on leaded 4* and from the general lack of any form of engine faults occurring. I have never suffered valve issues or bigend wear for example in any of the cars

I should think that modern oils and tolerances have a lot to do with that, rather than the fuel - it's 21 years since leaded 4* was available for sale here and 27 years since one could buy a car without a catalytic converter.

I've never had any valve, big end, crank or engine issues in cars either. They were common in the late 70s and 80s British tat I worked on in summer holidays at a local garage though...

[GiveMeABreak]

I use the odd tank of premium diesel specifically for its fuel cleaners / engine cleaning additives. It's the fuel system I want to preserve and help prevent injector clogging. There's then no need for an additional fuel cleaning treatment if you regularly use a premium fuel. I'm not really bothered about any performance gains or extra MPG - as I never get anymore than 43MPG on the last 2 cars with similar engines and only slightly more than that on the 2.0 110 on the MK I C5.

[mickthemaverick]

I take your point about modern oils and that may well be a contributer but tolerances no. My current cars are a nearly 20 and a 26 year old as have been the vast majority of my cars. In 2010ish when I started using premium fuel I was running a 1992 XJ40 and a 1984 Celica. The only car newer than 2001 I have ever owned was my 2007 Prius which was a company car (I owned the company) so my engines have generally been very old designs and hence the comparison to old 4* is valid.

An interesting test I saw at the classic motor show in Stoneleigh a couple of years ago showed a piece of blotting paper cut in half and one half soaked in standard shell and one half in VPower, both sourced from the local shell station. Both pieces were then put on an oven tray and ignited. After burning the standard fuel part had a thicker deposit than the Vpower side when the ashes were blown away. Read into that whatever you want but I was impressed!!