Fuel Economy And Trip Computer

[Guest MarkD]

Hi, this is my first post. The price of fuel is making me think about trading in my Scenic for a Picasso 1.6 HDi, which is supposed to do 13mpg better.

 

I test drove one today, and zeroed the trip computer before I started. First 5 miles was in town, and it showed 50mpg average. Then drove 7 miles at 60mph, instant figure was around 45mpg heading west, 75mpg heading east (because of the wind?); then 3-4 miles at 50mph, instant figure was 70-80mpg(!) and 3-4 miles on motorway at 70mph, showing still around 60mpg; then some slower stuff back to the garage. Overall it recorded 55.4mpg - slightly worse than the official figure.

 

Now that was pretty gentle driving, and I like to think I'm an economical driver - I get 51mpg from my Scenic, which is only supposed to do 44 - so I'd expected better. So I have three questions:

 

1. Has anyone compared the average mpg function on a Citroen computer to actual mpg (as calculated by filling the tank until the pump clicks off, zeroing the trip, then dividing the distance to the next fill by the amount of fuel you put in before the pump clicks) - and if so, was it accurate? I've heard some people claim that on Renaults, they give miles per US gallon, which is quite a bit down on UK mpg.

 

2. What's a reasonable mpg to expect for a long journey cruising at 70mph?

 

3. Read elsewhere someone saying his mpg dropped; he noticed oil leaking around the turbo and had it fixed, and mpg went up again. I did see oil leaking from above and to the left side of the engine (left of the car that is, so right as you're looking at it), but didn't pay any attention to what it was coming from. Is that where the turbo is on a Picasso 1.6HDi? Anyone else had experience of similar leaks? Are they common/expensive to fix/ do they usually affect mpg?

 

Thank you. This will help me not just to decide about this Picasso, but whether it's worth buying one at all.

 

Mark

[Johndouglas]

I have a fuel computer on my C5 and I enjoy checking consumption against varying speeds - sad isn't it? Mine is the 2ltr engine so expected figures will be lower than the 1.6. The highest figure I've ever attained was 60mpg at an average of 55mph over a 40 mile run. From that point, the higher the speed goes, the lower the consumption figure becomes. So at 70+ the consumption falls to 46mpg. Load, head wind or roof box will lower it even further. I also find it beneficial to switch off the cruise control on steep hill climbing.

 

Whether or not the Piccy's computer is as accurate as the C5, I don't know, but I find the speedometer agrees to within 1mph with satnav. Also over a return run from London to Malaga, I kept a record of fuel fills and later checked the consumption against the amount of fuel purchased. Both records more or less agreed on the fuel consumption.

 

Regarding oil dripping from the trunking. There's always a film of oil within the trunking to the turbo but probably there shouldn't be sufficient to drip. I haven't heard of it as a common problem, so it may just be a fault on that particular car.