Something odd with the new car - its remarkably economical compared to my other Charade.
The old lilac one would never in daily use exceed 55 mpg unless I drove very, very carefully.
I have been driving very normally in the new one and I filled up yesterday and got 62 mpg, genuinely without trying, infact as Im still adapting to driving a manual again, ive even had some episodes where I forgot to change into 5th and I did many miles at 40 in 3rd once, its too quiet I tell you.
Im not sure what to make of it. The only differences are the new car is a 5dr and it has a/c and alloy wheels. Other than that I cannot see why it would be so much better on fuel, its the same car, same engine, same gearbox, same gearing, its even the same year and does the same trips on the same roads as the last one did.
I suppose the logical conclusion is there was some extra drag on the lilac car rather than something special about the new one? Its worth noting that the combined figure for the car is 58.9 mpg, extra urban 68 mpg so its exceeding expectations at 62 already. I did once get 67 out of teh lilac car but that was doing a steady 60 on the A14 for 100 miles.
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>>The only differences are the new car is a 5dr and it has a/c and alloy wheels. Other than that I cannot see why it would be so much better on fuel, its the same car, same engine, same gearbox, same gearing, its even the same year and does the same trips on the same roads as the last one did<<
How about the tyres guvnor?
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New car has Goodrich on the back, nearly new Firestone on the front.
Old car had Pirelli P600 on the front, Hankooks on the back.
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>>its too quiet I tell you.
>>>>How about the tyres guvnor?
Is there a connection in the above ?
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Dirty air filter... slightly fluffed injectors needing some fuel system cleaner...
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Or a g inducing good thrash !
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>>Hanbrake dragging ?<<
The lilac car did suffer sequentially seizing brakes, all of which were stripped and cleaned up along with the handbrake, this reduced the mpg to 48, but it was up to 55 once fixed.
The funny thing is, you would the lilac Charade with 55k on the clock doing 15k a year to be less in need of a thrashing than a 25k car that has only done 4k in 3 years.
I havent get given the new car the beans because the cambelt hasnt been done yet and if it is 9 years old, I dont want to push my luck!
On paper id expect the new car to be less economical. Its done 300 miles since I picked it up so Im sure its loosening up a little but it will be a few more months before it really benefits from daily use.
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State of tune, weather, driving style, tyres, road surface, different length of comparison, different oil, different fuel,
All in all, far too many variables to make a decent comparison in a short(ish) space of time.
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>> Its done 300 miles since I picked it up
You can't expect to get a realistic economy figure in that short distance. I'd work it out over 5 or 10 tankfuls (from the same pump at the same station each time) to get a better idea.
A difference of only 1 litre from one fill-up to the next will alter the calculated economy figure by 4 or 5 mpg, and remember mpg is a logarithmic scale so the better the car's economy the greater effect any measuring errors will have.
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>>Is there a connection in the above ?<<
Course there is m8, some tyres have a lower rolling resistance than others and so will effect MPG.
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Do not discount build tolerances. At one time I had 2 x 1.25 Zetec Fiestas ( effectively from new), from the same model year, one was always quicker and more economical, nicer to drive than the other. When the cambelt was changed at 10yrs on the laggard it started to perform similarly to the other other one! The only conclusion was that the timing was marginal wrong from build.
PS The crankshaft sprocket is NOT keyed, it relies on setting pins and a tight bolt only.
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When I was doing my A-levels me and a mate got jobs at the local Pizza joint doing home deliveries. They had a pair of 1.0 metros, both the same age and similar mileage, but one ran better and was quicker. I remember we used to always rush to get there first to get the blue one. Last guy in got the lemon yellow Nova with an illuminated telephone on the roof....
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I was employed where we had three identical Peugeot Partner, diesel vans. One performed much better than the other two. The latters performance was dangerous when attempting to pull onto de-restricted roads.
I pulled the engine cover of one and found it wasn't getting anywhere near full throttle on the mechanical pump. A simple matter of pulling a 'hair-clip' type device off the throttle cable and re-positioning it.
I was asked to do the same to the other within a few days.
These things were supposed to have a PDI by a main dealer!
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The only valid way to measure fuel consumption is to average it over a long time period of time. I record every drop of fuel I buy and the odometer reading, and calculate the average consumption for each month, and the overall average consumption since I bought the car.
What I find is .........
(a) Fuel consumption varies with journeys travelled, and driving style.
(b) Fuel consumption varies from one month to another depending on the the weather ~ it's generally better in summer than in winter.
(c) Fuel consumption improves over the first 10,000 miles or so as the car loosens up, and then deteriorates as the mileage increases.
If you want a valid figure then ignore single journeys, brim to brim and fuel trip computers.
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Im guessing my measuring method is consistant because on the Kenari I got 42-44 mpg every single week.
I work it out per tank and per month for my records. Thats why I was able to look back at the lilac car and see that I had never cracked 60 mpg doing my daily commuting about the countryside.
I shall of course keep an eye on it, it will be filled up again by the weekend so ill see if I get a similar result and then going forwards. Im not complaining if it will do a consistant 60 though, very welcome!
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Two identical cars, very different consumption - Dog
