TheRecklessEngineer Posted April 4, 2007 Share Posted April 4, 2007 Just been out to france and back and noticed something weird going on with my fuel consumption. 300 TDi disco - in England I get about 28mpg cruising at 70mph Filled up with french diesel and suddenly I'm getting 35mpg - still at 70mph. Didn't notice any difference in power though. Any suggestions? Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted April 4, 2007 Share Posted April 4, 2007 Well, I know you said 'cruising', but are you sure its not something to do with less traffic jams / braking / accelerating? Al. Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted April 4, 2007 Author Share Posted April 4, 2007 Nah - it was 70 all the way. Filled up in England...left at 1am for dover - no traffic. That tank got 28mpg. The next tank got 35. Maybe my maths is out...but I did wonder at one point if the fuel gauge had jammed... Quote Link to comment Share on other sites More sharing options...
Anglo-Frenchman Posted April 4, 2007 Share Posted April 4, 2007 Damn! You've discovered the mystery of french diesel - now you'll all want some! Seriously though I don't know what the answer is. I usually do about 9litres/100km (which is the unit of measure that the French use for consumption rather than MPG) and which equates to about 30mpg which for a 14 year old 200tdi with a full Brownchurch roof rack (so the aerodynamics of a sub-Post Office) has always struck me as pretty good! Quote Link to comment Share on other sites More sharing options...
steve b Posted April 4, 2007 Share Posted April 4, 2007 No explanation for it but I got 32 on a run from Charente to Calais with my LR (200tdi)...best I get here is 28-30 .Mind you as Al says in GB you're lucky to get an hour at a constant , in France it's a case of how big is your tank = x hours of a constant speed (apart from the looooong hills ) Steveb Quote Link to comment Share on other sites More sharing options...
jules Posted April 4, 2007 Share Posted April 4, 2007 French tarmac has less friction which means less drag as well as better road maintenance and better roads generally. My Camper was better on fuel and much faster in france than it ever was in the uk. Quote Link to comment Share on other sites More sharing options...
kkk2 Posted April 4, 2007 Share Posted April 4, 2007 Is there not a percentage of biodiesel in the French fuel? this would account for the better economy Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted April 4, 2007 Share Posted April 4, 2007 Maybe its because its hotter here - the lower air density means less drag on the car, giving better efficiency! Al Quote Link to comment Share on other sites More sharing options...
Anglo-Frenchman Posted April 4, 2007 Share Posted April 4, 2007 I do think that being able to drive without any significqnt hold-ups, gear-changing and rolling at a constant speed helps raise fuel economy greatly. Where I live, it is not unusual to drive for perhaps 25km without seeing another car sometimes and I cannot remember the last time I was stuck in traffic......oh yes I can, it was in 2005 approaching the ferry port in Newhaven at 2330hrs! Quote Link to comment Share on other sites More sharing options...
David_LLAMA4x4 Posted April 4, 2007 Share Posted April 4, 2007 Maybe the tarmac is flatter and there is certainly less hold ups but neither is the fuel in France the same poor quality stuff we gat!! Our fuel is in general not only very dear but also of a lower grade / octane / whatever than French ( and Spanish ) fuel... I always get much better economt in my 110 when in France/Spain. Same applies to petrols - it's like running on V-power or other brands of the same stuff but you don't have to pay the extra for it that we do..... I say it is about time we had another fuel strike David Quote Link to comment Share on other sites More sharing options...
Gromit Posted April 4, 2007 Share Posted April 4, 2007 well as a corollary to your experience, when I headed to France in 2003, I found an increase in power when I first filled up at a French petrol station. At the time I just put it down to it being the first time the 110 had been run flat out for a few hours and had cleared out some carp. Maybe it was higher octane diesel Quote Link to comment Share on other sites More sharing options...
Les Henson Posted April 4, 2007 Share Posted April 4, 2007 I always thought that France was more downhill than this country You can get off the ferry at Calaise and then roll all the way to Germany (or whoever it is next door) Les. Quote Link to comment Share on other sites More sharing options...
simonr Posted April 5, 2007 Share Posted April 5, 2007 As Jules said, I have heard that it's down to tarmac with lower kinetic friction. The up sides are lower noise and lower fuel consumption, down side is longer stopping distances. Though - I like Les's thinking! Si Quote Link to comment Share on other sites More sharing options...
GBMUD Posted April 5, 2007 Share Posted April 5, 2007 Making the annual off-road journey to and from France I have noticed an improvement in performance. I always fill up at the BP station near the docks before boarding the ferry for home. Coming off the ferry at Newhaven you are inevitably stuck behind a granny/camper/caravan/truck etc. for about 8 miles. As soon as you get onto the A27 there is a short uphill stretch with an overtaking lane which really shows up the difference in my 90Tdi! It pulls much, much better and I can pass people with ease which would otherwise be difficult/impossible. IIRC bio-diesel has more calories per unit than dino-diesel so perhaps the 5% makes the difference. SteveG was telling me at the weekend that his RR TD6 developed a mis-fire while driving down through France to Spain. When he got back to the dealer in the UK they blamed the French diesel. Steve reminded them that they sell RRs in France too and so that cannot be the problem? Chris Quote Link to comment Share on other sites More sharing options...
Simon Smith Posted April 5, 2007 Share Posted April 5, 2007 My 110 always performs better on french diesel compared to english. The improvement always stays when I get home until I have to fill with english rubbish. This week I poured some Derv from my local filling station into a clear jug, It was milky white with what appeared to be fatty globules in it. The chipfat I get from the chippy is cleaner BEFORE I filter it. Quote Link to comment Share on other sites More sharing options...
Steve King Posted April 5, 2007 Share Posted April 5, 2007 My 110 always performs better on french diesel compared to english. The improvement always stays when I get home until I have to fill with english rubbish.This week I poured some Derv from my local filling station into a clear jug, It was milky white with what appeared to be fatty globules in it. The chipfat I get from the chippy is cleaner BEFORE I filter it. I think you're correct Simon. I'm sure that most if not all French diesel has a large percentage of bio-diesel that improves performance. Steve Quote Link to comment Share on other sites More sharing options...
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