John's Greek C5

[myglaren]

You should be able to change that to MPG.
Poke the button on the end of the washer stalk and it should cycle through various options including MPG~dl/100km.

6.7/100km does sound excessive. It's a long time since I thought of fuel consumption in those terms but the Volvo 240s we had for work were around 4.5 - and Volvos are notoriously thirsty (I had one and can confirm), as are most SAABs but one of the lads had a SAAB - 99 I think with a V4 and that used around 3.2/100.

[white exec]

= 42.16mpg

[myglaren]

= 42.16mpg

I should set mine to metric - that is more than I get
Will be filling up tomorrow most likely so a good opportunity.

[moizeau]

the lads had a SAAB - 99 I think with a V4 and that used around 3.2/100.

Did he do a lot of downhill driving? That's 88mpg!!

[mickthemaverick]

= 42.16mpg

There is a big discrepancy between your figure and mine quoted above Chris, mine is 62/1.78, how did you get yours

[moizeau]

Litres used per 100 kilometres.. 4.54 litres in a gallon, 100km is 62.13 miles. So if you had a reading of 4.5/100 (l/100km) that would be 60mpg.

[RichardW]

I think you've converted yours into US Gallons, Mick.... 6.7 litres @ 4.54 litres per Imperial Gallon = 1.48 gallons, @3.75 litres / US Gallon = 1.78 gallons, as you have quoted.

I don't think the 6.7 figure is right, I can't see a 1.8 C5 doing over 40 - I would expect it to be around 25 around town, and possibly 30 if treated gently on a run. 25=11.3 l/100km / 30 = 9.4 l/100km.

My Dad used to have a 1.8 8V Xantia - he got it down to 18mpg average over a 300 mile run towing a caravan hard!!

[mickthemaverick]

Litres used per 100 kilometres.. 4.54 litres in a gallon, 100km is 62.13 miles. So if you had a reading of 4.5/100 (l/100km) that would be 60mpg.

Thanks Pete. I can see where I went wrong. Instead of calculating litre to gallon conversion I used an app and selected US gallons in error . I just checked the app for uk gallons and the result is the same as Chris at 42.17 mpg. So ignore my previous numbers John and go with 42 mpg which is about what I would expect from the 1.8. So if it appears to be drinking juice and smells I'd definitely go leak hunting! Good luck

[mickthemaverick]

I think you've converted yours into US Gallons, Mick.... 6.7 litres @ 4.54 litres per Imperial Gallon = 1.48 gallons, @3.75 litres / US Gallon = 1.78 gallons, as you have quoted.

Quite right Richard, thanks, corrected above in parallel with your post

[moizeau]

Direct conversion table here
https://www.calculateme.com/gas-mileage ... ritish-mpg

[RichardW]

All gallons are equal, it's just some are more equal than others!! We often come across this problem with old pump data - performance curves with stated flows in 'Gallons per minute' - US or imperial??? We often have to work back through the power and efficiency curves to find out which!!

[myglaren]

the lads had a SAAB - 99 I think with a V4 and that used around 3.2/100.

Did he do a lot of downhill driving? That's 88mpg!!

Most likely an error with my memory, I think the batteries are about depleted

[GiveMeABreak]

The manufacturer's figures for this engine (Petrol 1.8 16V), so 6.7L / 100 KM is well within the Extra Urban to Combined categories.

Manual

Use	MPG	L / 100 KM
Urban	26.6	10.6
Extra Urban	47.1	6.0
Combined	36.7	7.7

Auto

Use	MPG	L / 100 KM
Urban	23.0	12.3
Extra Urban	45.6	6.2
Combined	33.6	8.4

[johnnyj]

Hi folks and thanks for all the mathmatical discussions. I'm afraid maths just isn't my thing, so I took a photo of the LCD today after a trip out. Here are the characteristics of the trip:

- Cold start-up
- Avg speed probably 60 KM/H
- Country roads
- Combo of 3rd, 4th and 5th gear
- Distance about 7.5 KM

The read-out is as in the photo showing (I think!) the average consumption. Looking at Marc's table, it looks about right, wouldn't you say? But I will certainly look at the plugs, air filter and injection areas discussed.

Cheers guys

John

[mickthemaverick]

Yes that works out to 32.1mpg which is about right, so the fumes are your only fuel issue to resolve.