running costs of my old car vs new car help

kelevraz

right im really not good at working this stuff out and i have tried really hard to find a calculator inline that will tell me exactly what im looking for, so to make it really simple for people

currently have a 1.4 ford fiesta zetec (petrol), and i get about 360 miles out of a full full tank, currently it costs me about £50-£55 to fill up my car

im buying a 1.8 focus (petrol)

can someone please give me a rough idea how much it would cost to fill up a 1.8 and a 2L, and how many miles they would last for, like i said, ive tried to figure it out online, i didnt really want to ask on here because i know to alot here it seems like an obvious question, but i cant find what im looking for, and i have no idea how to figure it out myself

a 2 litre version of the car i want wont cost much more on insurance, but my girlfriend is convinced that it will cost me so so much more than a 1.8 petrol wise, would like to know if this is true

Guest101

Well it depends on the size of the fuel tank but i think they are the same size in all the focus's. So the cost to fill up wont be any more.

What you need is the MPG, which is actually more affected by your driving method, than the car itself. Changing gears at lower revs, keeping top speed down, not over accelarating, not over braking etc etc.

It's a common misconception that a bigger engine will always cost you more in fuel.

A 1.4 litre engine will produce x amount of horse power (which is needed to move the weight of the car)

A 1.8 or 2.0 will produce more horse power, so move the weigth more easily.

So with careful driving, you can potentially save money on a higher engine size.

The point then comes into it, if the engine is producing excess energy, ie burning fuel for no effect.

I'm not saying you'll defo be better off, i'm saying check what MPG you do currently and what your new car is capable of achieving, that's your aim.

Tiexen

Approx 35mpg* 55ltr tank £70 to fill

*Real Life Fuel Economy Register

buglawton

For fuel cost, learn the mpg figure of the outgoing and potential incoming cars, from that you can calculate the weekly fuel spend.

Big engines work out better on insurance for older drivers with long no claims records.

What about the tax disc every year? Bigger engines can double the cost of that.

But if you 'just fancy' a more powerful car, why try to justify the cost?

kelevraz

to be honest, the way its being put to me doesnt make it sound like it will be anywhere as expensive as i thought, i expected someone to tell me that it would cost me something silly like £85 to fill my tank in a 1.8, i do not mind the tax cost

its just it seems that, im finding nicer cars in 2L version for my budget than i am 1.8, im not really sure why but there you go, so if ultimately it works out that im going to be paying hardly any more then ill just go for the 2L i guess

Ultrasonic

First up, there is a very good chance that from a purely financial point of view you will be best off keeping the car you already own.

As others have said you need to know the mpg you are getting from your current car to make comparisons. To measure this, fill your fuel tank until the pump stops (first click). Either note your total mileage or if zero your trip counter. Drive as you normally would, using most of the tank of fuel before coming to refuel. When you refuel, do so again till the first time the pump stops. Note how many litres of fuel you have put in and the distance you have travelled since you last filled up.

To convert the volume of fuel used from litres to gallons divide by 4.546. Your economy in mpg is then the distance travelled divided by this volume.

To get an idea what other cars get in the real world, check out http://www.honestjohn.co.uk/realmpg/.

Then compare annual fuel costs based on your mileage. BUT you also need to factor in the cost of buying a replacement car before deciding that is worth doing.

Generally speaking larger engines offer lower mpg (as you'll see from the Honest John website), but there will be exceptions.

Ultrasonic

kelevraz wrote: »

i expected someone to tell me that it would cost me something silly like £85 to fill my tank in a 1.8

You really need to stop thinking about the cost to fill a tank. It is utterly irrelevant. If one car has a 40 L tank and another a 60 L tank, it will cost 50% more to fill the tank of the second car. But if it then lets you drive 50% further then the cost per mile is exactly the same. It is the cost per mile that you need to be thinking about.

Ultrasonic

kelevraz wrote: »

its just it seems that, im finding nicer cars in 2L version for my budget than i am 1.8, im not really sure why...

It will almost certainly be because the 2 L version is less economical, meaning both fuel and road tax costs will be higher than the 1.8 L version. Or that people assume it will be.

Cornucopia

Miles per tank is much more of a relevant (and easy) measure.

My last few cars have been returning 500-600 miles per tank, which I'm very happy with. On long trips, they've been even better than that.

I would think twice before going back to a car with 250-350 miles per tank.

OddballJamie

Cornucopia wrote: »

Miles per tank is much more of a relevant (and easy) measure.

My last few cars have been returning 500-600 miles per tank, which I'm very happy with. On long trips, they've been even better than that.

I would think twice before going back to a car with 250-350 miles per tank.

It may be easier to say I can do x miles per tank but fuel tanks are not a standard size across all cars. It's about as useful as saying a full tank lasts me a month.

Ultrasonic

Cornucopia wrote: »

Miles per tank is much more of a relevant (and easy) measure.

Miles per tank is useful in terms of considering practicality, but is of no help in determining running costs (which is what this thread is about).

Not sure what age/model of Focus is being considered, but looking quickly it does seem there's little in it in terms of fuel economy between 1.8 L and 2.0 L models so on that basis you may as well go for the more powerful car. But what you should probably be doing is trying to find out which might be the more reliable engine as well. I can't help you there I'm afraid.