Fuel/MPG calculator

Anica85

I'm looking to buy an economical car, preferably used. I've been looking at different fuel calculators to see how much my commuting will cost compare to driving. I found http://www.motors.co.uk/fuel-calculator/ to be quite useful, but because I dont have a car, I dont know how accurate those tools are.
Any thoughts?

BeenThroughItAll

Anica85 wrote: »

I'm looking to buy an economical car, preferably used. I've been looking at different fuel calculators to see how much my commuting will cost compare to driving. I found http://www.motors.co.uk/fuel-calculator/ to be quite useeful, but because I dont have a car, I dont know how accurate those tools are.
Any thoughts?

They're only as accurate as the figures used. The calculation is incredibly simple, but if you assume the MPG figures the manufacturers give are correct, you'll likely be very disappointed if you come to actually buy the car...


If a manufacturer quotes an MPG figure, reduce it by 20% and you'll be much closer to what you'll achieve in real life for most manufacturers' vehicles.

AdrianC

You don't need a calculator website.

You know how much fuel costs per litre.
You can easily find the official economy figures for any given car. Take 25% off them.
The only other piece of information you need is that there are 4.54 litres in an imperial gallon. Ignore anything that says 3.8 - that's a US gallon.

So if fuel around you is £1.18 a litre, and you will realistically be doing 40mpg, then your fuel cost will be...
£1.18 x 4.54 = £5.36/gallon
£5.36/40 miles = 13.4p/mile
So a 200 mile round trip will cost you about £27 in fuel.

Then remember that fuel is far from the only cost. Depreciation, maintenance, insurance, finance costs...

10,000 miles per year will cost you about £1,340 in fuel. It may easily cost £1,500 in depreciation and finance costs, £400 in insurance, £50 in VED, £300 in maintenance...

So that £1,340 annual fuel cost is actually just over £2,500 in total. 25p/mile.

Strider590

I think fuel saving is a red herring.

When I bought my first big car in 2008, it was 4 years old, £3000. The same aged small car was more like £5500-£7000. Nobody wanted big cars, everyone was obsessed with fuel prices.

My car did 34 mpg, the smaller cars I looked at were more like 35-38mpg.......... The way I see it, what I saved on the cost of the vehicle, more than covered the extra fuel I used over the 8 years I owned that car and during those 8 years I enjoyed all the standard features that large cars come with, but small cars do not and it goes without saying that my 1.8 was much more rapid than some piddly 1000cc car engine.

This website is a testament to the fact that in order to really save money, you need to stop listening to marketing hype, stop listening to bad advise from clueless people and start doing some serious research before parting with your cash.

MataNui

Small cars dont always mean better fuel efficiency. I read an article the other day that compared manufacturers mpg figures against real world values based on engine size. The variance is much greater on the small engines. So much so infact that a 3litre engine could return similar real world mpg to a 1.6.

The explanation was that the manufactures tests involve gradual acceleration to set speeds. In the real world this doesnt happen. Smaller engine cars in particular need to rev much higher for much longer in the real world than on test. Large engines though dont as they usually have more torque at lower revs and cruise at lower revs. So the test is much more accurate for the bigger engine cars.

DoaM

BeenThroughItAll wrote: »

If a manufacturer quotes an MPG figure, reduce it by 20% and you'll be much closer to what you'll achieve in real life for most manufacturers' vehicles.

According to this website my car has a Combined figure of 5.4 l/100 km = 52.3 mpg. My actual (recorded in a spreadsheet) average economy is 51.3 mpg (or 5.5 l/100 km). So in my case the published figures are quite close.

(My best economy for a tank of fuel has been 61 mpg, and the worst 39 mpg).

BeenThroughItAll

DoaM wrote: »

According to this website my car has a Combined figure of 5.4 l/100 km = 52.3 mpg. My actual (recorded in a spreadsheet) average economy is 51.3 mpg (or 5.5 l/100 km). So in my case the published figures are quite close.

(My best economy for a tank of fuel has been 61 mpg, and the worst 39 mpg).

Hence why I said "most manufacturers' vehicles". It's been shown that some manufacturers real returns are much closer to those claimed than others. Is yours a DSG?


VW claimed 58.9 combined for the manual 2.0TDI 140PS and 53.3 for the DSG (non BlueMotion) in the Golf Mk6 brochure I have in my desk drawer (from 2010). So if yours isn't a DSG, it's 7.6MPG down on official claims, or ~13%

DoaM

Mine is a manual (6 speed), 2.0L 140 PS Bluemotion.

I did wonder about the figures on that website I linked ... the 58.9 you've quoted does ring a bell with me. (Maybe the website uses real-world reported figures?)

BeenThroughItAll

DoaM wrote: »

Mine is a manual (6 speed), 2.0L 140 PS Bluemotion.

I did wonder about the figures on that website I linked ... the 58.9 you've quoted does ring a bell with me. (Maybe the website uses real-world reported figures?)

That's interesting. The numbers quoted for the 2.0L 140PS BlueMotion by the VW brochure are:


Urban: 52.3
Extra-urban: 74.3
Combined: 65.7


So by that measure, your real world consumption is indeed ~22% below VW's claims.


VW actually still have a 2010 brochure available for download as well (2.0TDI PS BMT figures on page 40). My paper one was from July 2010, but this one is from December and the numbers are the same: http://cdn.volkswagen.co.uk/assets/common/pdf/brochures/golf-vi-brochure.pdf

forgotmyname

My car does 57mpg..

err no it does 48mpg...

no again it does 38mpg....

and NO AGAIN... it does 28mpg....

Which one is correct? The answer is ALL of them. Real world average MPG over a FULL tank of fuel working out how much it cost to fill it and not relying on a trip computer etc.

57mpg trips to the coast with some traffic at either end otherwise it could have done a bit more.

48mpg general journey's outside busy periods.

38mpg journey's during busy periods and queueing traffic. A 10 minute journey can take 40+ minutes.

And finally 28mpg... Winter journey's with snow and ice etc.

All with the same car, and no its wasnt broken or running poorly, just short winter journey's and doing 0 MPG whilst the engine warmed and i cleared the windows.
I wont drive off without perfectly clear windows.

[Deleted User]

My car would es a combined figure of 65 mpg in reality I have been getting 48 mpg for mixed driving to by and I have a very light right foot and believe I couldn't drive anymore economically than I do without leaving all passengers at home!
It's still good economy compared to a lot of cars though.