A Kia Rio 1.1 CRDi has an mpg rating of 88.3, while a Ford Fiesta 1.6 TDCi Econetic provides 86 mpg – would this slight difference in diesel consumption significantly affect the fuel overhead of a lease? Keep reading to find out…

Leasing offers a number of benefits for motorists, most notably: the option to upgrade their selected vehicle every few years, no worries regarding depreciation and related resale value, and the inclusion of some maintenance as part of the fixed monthly payments.

The vast majority of drivers seek a contract hire deal which comprises low monthly fees, but selecting a car that also offers decent fuel economy is important for ensuring the overall cost of a lease remains wallet-friendly. It is also important to know how any proposed fuel tax inflations will affect the cost of running your leased motor.

It is common knowledge that electric (EV) and hybrid (HEV) models offer some of the very best miles per gallon ratings, but the majority of lessees choose a petrol or diesel car due to their lower OTR retail prices and, therefore, lower monthly lease charges.

If you’re one of the many potential lessees trying to decide between several different petrol or diesel models, you should use Thisismoney.com’s fuel calculator to compare the potential annual fuel overhead for each, before signing on the dotted line of any contract hire agreement.

For more car leasing calculators including depreciation and insurance calculators see the Lease Your Next Car guide to the costs involved when leasing a vehicle.

How to use Thisismoney.com’s fuel calculator

Step 1
Upon arriving at the easy-to-use calculator, you will find all fields are blank. There are three you need to complete to see results calculated:

Annual mileage: Here you should enter the maximum agreed mileage included in a lease deal of interest (NOTE: 15,000 is a common mileage allowance, so use this figure if you’ve not yet checked out any specific lease contracts). Although you may not use every included mile in any year, using the maximum allowance for comparative purposes is advised

Miles per gallon: Enter the mpg figure for one of the motors you are interested in leasing in this field

Current price per litre: Fuel prices change regularly, and vary between different regions of the country. You should enter the current average price per litre for your region in this box

Once these figures have been entered, the fields below should automatically update, but if they do not click the red ‘Calculate’ button.

The figures entered in the top three fields above represent a Kia Rio 1.1 CRDi lease, offering a maximum mileage allowance of 15,000 per annum. You can see that should all allowed miles be utilised, the car would burn around £1,096 in fuel annually.

But how does this compare to the aforementioned Ford Fiesta 1.6 TDCi Econetic (assuming mileage allowance is matched)? Simply change the fields as necessary to find out:

Here we can see that fuelling the Ford Fiesta TDCi would cost just £29 (approx.) more each year than the Kia Rio CRDi, as a result of the 2.3 mpg difference.

Step 2
On the bottom half of Thisismoney.com’s calculator, you will see there are fields for calculating how potential fuel hikes and (less likely) drops could affect the total annual fuel overhead for your vehicle.

A potential 5p per litre increase across the UK has been discussed recently by many news publications – let’s look at how this would affect the cost of running the Kia Rio CRDi if implemented (simply insert any proposed cost per litre change into the box):

Here we can see a 5 pence increase per litre would make the Kia Rio CRDi £38.61 more expensive to run each year, if the same 15,000 miles were covered.

NOTE: While Thisismoney.com’s calculator mentions an increase in fuel duty planned for August 2012, this initiative was cancelled by UK Government. Current duty for petrol, heavy oil and biodiesel is 57.9 pence per litre – the same sum the calculator utilises. For more information, please see HMRC’s latest official fuel duty rates document.

Need more advice before deciding which vehicle you should lease? If so, seek impartial, expert advice from an independent car leasing specialist.