How do my MPG calculations compare?

[Oil Burner]

Hi all,

Just been doing some old school mathematics on paper regarding my past years fuel usage, cost and miles covered and wondered if you guys think I am getting the right figures.

I have a 2005 (55 plate) S60 Euro 3 Geartronic

Here are my scribblings;

12 months equals 880 litres of BP Ultimate Diesel at £1.30 per litre (average) which equals £1144 per year

12 months mileage is approx 6000 (maybe +500 on that as I am estimating)

So that is 194 UK Gallons / year

And that equals 31 MPG

My daily commute is 10 miles each way, 5 days a week on 90% 'A' Roads , but lately there seems to be lot of crawling in traffic for say 10 mins in the morning and 15 minutes at night.

Weekends I will only do about 6 miles just local probably 1.5 - 2 mile journeys.

Do these figures sound about right for my car and driving cycle?

The Average on the Dashboard is showing 38.6 mpg, but when the traffic was clearer last year it hovered around 40 - 41 mpg.

[Tub Thumper]

I've a 2004 V70 D5 manual and over the 45k miles since it was re-mapped I've averaged 43.1mpg (measured). Prior to that it was 41.3mpg. The trip computer over-reads by 5-6mpg per fill - best ever was +0.1mpg (lots of short trips), worst was +10mpg (lots of motorway cruising).

Given your traffic and short journeys from cold, then I suppose 31mpg might be about right.

[Oil Burner]

Thanks for the response Tub Thumper

I think your assessment is correct regarding my driving conditions.

Have reset the average mpg and speed info today and see how that develops over next week.

For the mpg I am getting I am seriously considering switching to a modern petrol engined vehicle.

[Veefor]

Am I wrong but aren’t diesels a more expensive way to travel if your doing less than 20,000 miles a year?
As in short trios kill diesels or at least lead to costly repairs,car doesn’t warm up,properly etc etc
Diesel costs more and many petrol cars do more to the gallon than diesels anyway?

[Oil Burner]

Just reporting back after a weeks commuting.

So after re-setting the MPG and average speed readouts last Sunday I have done a weeks commuting and the figures are as follows;

Distance travelled 105 miles ish !

Average speed 22 Mph Hmm

Average MPG 38.9

So the mpg is back up to what it was give or take a few points.

And I did not really drive like a granny, just steady keeping up with traffic and a few heavy foot moments that I use to keep my turbo vanes free. (Yes it does work and has cured my limp mode)

[Simon Jones]

Originally Posted by Veefor

Am I wrong but aren’t diesels a more expensive way to travel if your doing less than 20,000 miles a year?
As in short trios kill diesels or at least lead to costly repairs,car doesn’t warm up,properly etc etc
Diesel costs more and many petrol cars do more to the gallon than diesels anyway?

That doesn't really make sense. There is little correlation between 20,000 and short trips. Someone doing 20k per year is averaging 55 miles a day so while its possible they do 10 trips a day of 5.5 miles (which would be bad for a DPF), it's more likely they are are doing a couple of 25 miles commutes a day.

Equally, that 20,000 annual mileage could be someone doing 190 motorway miles on a Monday to travel to place of work and 190 miles back again on a Friday. That would not constitute a short trip.

[I-S]

The mileage you're getting doesn't seem out of bounds, especially as your car is auto and is now over 12 years old.

On a fairly similar sort of commute (11 miles each way, two bursts of 50mph A-road, plenty of 30mph stop-start) our 2011 V70 D5 Geartronic returns mid-30s.

Simon is correct that low mileage doesn't necessarily imply short journeys. In november we bought a Nissan Leaf, which is fantastic for commuting (already warm when you get in it, hoof it from the off as there's no engine warm up, costs pennies to fuel, far more responsive drivetrain around town, no excess wear from short journeys, etc). That means that the mileage on the V70 has dropped very significantly, but those miles are long journeys where it gets to warm up and run nicely in the best possible operating range. MPG on the V70 is up significantly even though mileage is down.

For your annual mileage an EV would seem to be an excellent fit if you have a driveway and/or garage.