MPG in towns / cities and different size engines

Buster_Danog

I am trying to work out the pros and cons of getting a bigger car in relation to fuel consumption. Right now I am driving an 18 year old Golf 1.3 and with the short journeys I do I am getting around 25mpg.

Could anyone tell me roughly what mpg they get in city traffic especially with 1.6 litre or 1.8 litre engines? I would especially like to hear from anyone with an older car as if I do get something bigger the chances are it will be at least 14 years old. I am looking right now at something like a BMW 316, or even an Audi 1.8l. It just depends on how much extra I will be forking out on fuel.

I have done some rough estimates from internet posts I found and have estimated I will be paying at least an extra 20% to do the same miles I am doing now, but it could be worse than that. I tend to be put off by the idea of older diesels, but I suppose that is because I have never had one and for some reason I consider old diesels to be more problematic - whether that is true or not.

Conor_3

You'd get about the same. Nothing wrong with old diesels apart from the fact they're not as powerful for the same engine size as new ones. If they were bad, taxi drivers wouldn't touch them but virtually all taxis have been diesel for decades.

Badger_Lady

I get 40mpg out of my 1.6, but that's because it's a lightweight 2-seater Honda and I drive very efficiently... my sister drives a 1.8 auto Vectra estate that's constantly piled up with heavy items and is lucky to get 12mpg.

(We both drive to work every day, about 4 miles through a city each way)

kaya

c220 cdi mercedes estate 05 plate, average 37mpg, 33 mpg around town, 48mpg on a run if driving like Miss Daisy

hewhoisnotintheknow

i reckon you would be better off spend 1000 and buying a little petrol, something like a saxo, polo, fiesta, 106, ka etc

Cardelia

53 plate BMW 316i (but a 1.8 engine) - around town I get 32-33 mpg but this goes up to 38 mpg on motorways. I'm sure it'll go above 40 mpg if I stick to the speed limit though.

movilogo

As a very rough estimation, fuel consumption from engine size (petrol) can be found from following formula

fuel economy in km/L = -4.25 * (Engine size in L) + 21

where engine size between 0.8 to 3.0 L.

1 km/L = 2.82 MPG

thescouselander

movilogo wrote: »

As a very rough estimation, fuel consumption from engine size (petrol) can be found from following formula

fuel economy in km/L = -4.25 * (Engine size in L) + 21

where engine size between 0.8 to 3.0 L.

1 km/L = 2.82 MPG

Not sure this works so well. I just tried it for a few cars I have owned and it doesn't seem to add up. For example, it reckons my old Mk2 MR2 (2 litre) should have done about 35 MPG but there is no way it managed that. Also the formula says my curent car (a BMW 330) would only do 23 mpg - actually this is the worst case in my experiance and I often get much better than this.

In practise I have found that the MR2 and BMW actually use about the same amount of fuel with the BMW only using slightly more. I dont think engine size ia always a good indicator of fuel economy.

hewhoisnotintheknow

the biggest variables in fuel economy is peoples right foot and where they are driving

Conor_3

hewhoisnotintheknow wrote: »

i reckon you would be better off spend 1000 and buying a little petrol, something like a saxo, polo, fiesta, 106, ka etc

If you're doing short town journeys, you want a diesel purely because it doesn't spend any part of the journey running on "choke" (or cold start) which uses more fuel than when up to temperature.

darich

Many places say that diesels are only more economical than petrol engines when you drive more than around 15k per year. This is due to the increased purchase cost and higher maintenance. I've never had a diesel so I'm not sure how accurate that is.