If I took a 1L car for a drive, then took a 2L car for the EXACT same drive....

... how much more would it cost me in petrol?

What I am trying to get at is 'Does a 2l car use much more petrol than a 1l car'?

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Reply 1

FXX

Depends on the car, fuel type and journey.

Reply 2

Mr Tall

it'll use twice as much

Reply 3

FXX

Original post by Mr Tall

it'll use twice as much

It really won't.

Reply 4

Harley SMU

It would depend on the age of the car(s), whether they're turbocharged or naturally aspirated, auto or manual to name just a few factors

Reply 5

Alfissti

Original post by Runninground

... how much more would it cost me in petrol?

What I am trying to get at is 'Does a 2l car use much more petrol than a 1l car'?

Depends, it is rather unlikely that there is a car has both a 1.0l and a 2.0l engine as an option to it.

On average a 1.0l Opel Corsa type car should return somewhere between 40-50mpg

A 2.0l Opel Astra should do 25-40mpg.

Reply 6

uberteknik

Original post by Mr Tall

it'll use twice as much

Absolute tosh.

There are so many other factors not least of all fuel efficiency, power to weight ratio, aerodynamic drag, driving conditions, driving style/habbits etc.

Look at the fuel economy specification (distance/litre) for urban, extra urban and combined fuel economy figures and cut them back by 20% because they tend to be inflated by the manufacturer.

Reply 7

jusdorange

Original post by FXX

Depends on the car, fuel type and journey.

this.

the 2.0l might even be more economically since you don't need to rev the nuts off it

Reply 8

traintracks1995

Original post by Runninground

... how much more would it cost me in petrol?

What I am trying to get at is 'Does a 2l car use much more petrol than a 1l car'?

All other things equal about 33% more for the 2 litre

Reply 9

FXX

Original post by traintracks1995

ll

All other things equal about 33% more for the 2 litre

Really? So how much more do you think it costs me to run my 3.2 compared to my friends 1.0?

Reply 10

DotDotCurve

Original post by FXX

Really? So how much more do you think it costs me to run my 3.2 compared to my friends 1.0?

53%

Reply 11

Camoxide

Depends.

If you drive it faster than you would the 1.0 liter it's going to use more fuel.

A 2.0 litre is going to be heavier as well so more fuel to use.

It's not going to use twice as much though.

Unless you put your foot down.

Reply 12

traintracks1995

Original post by FXX

Really? So how much more do you think it costs me to run my 3.2 compared to my friends 1.0?

All things held constant I would estimate a 3.2 litre engine to use 80% more fuel than a 1 litre

Reply 13

JC.

Original post by traintracks1995

ll

All other things equal about 33% more for the 2 litre

Doesn't work like that.

To use a real wolrd example that I've got experience of... a '75 MGB wityh a 1.8 4 cylinder B series on a run, set up properly, will return about 28mpg.
The same car fitted with a 3.5 litre Rover V8 in standard trim, set up properly, will return about 30-32mpg.

The engine double the size with double the cylinders is MORE economical on the same route, same conditions and at the same speeds.

Similarly, again with real world experience, a 2.9 litre Jaguar XJ40 will consume more fuel than it's 4.0 litre twin cam equivalent.

Reply 14

traintracks1995

Original post by JC.

That surprises me. If you drive a set route in say a 1 litre Passat at a comfortable speed, and then drive the same route again in a 2 litre Passat at the same speed and same car weight, I would expect the 1 litre to be more economical. I get that if you were to thrash the 1 litre then the 2 litre wouldn't have to try as hard to keep up and would then be the more economical engine.
Were you thrashing the 1.8 and then 3.5 didn't have to work so hard to keep up ?

Reply 15

JC.

Original post by traintracks1995

If you think about it, the smaller engine has to work harder to lug around the same weight.
Whereas on the other hand, the larger engine is barely ticking over to do the same job.

I don't "thrash" cars on the road... save that for the track. :wink:

Reply 16

Maccees

Original post by traintracks1995

ll

All other things equal about 33% more for the 2 litre

You really need to stop pulling numbers out of your arse and stating them as fact.

Reply 17

traintracks1995

Original post by JC.

I get your first point theoretically, but I would imagine that this doesn't happen in the real world. Otherwise a BMW 750i would use less fuel than a 728i because it's barely ticking over to do the same job. (Granted the 750 weighs slightly more).

Original post by Maccees

You really need to stop pulling numbers out of your arse and stating them as fact.

What numbers ?

Reply 18

JC.

Original post by traintracks1995

Well, going back to my point... an XJ40 with a V12 would use more fuel than both the 2.9 and 4.0 litre AJ6 engine versions of the same car.
Primarily because the V12 can trace its roots back to the 50's...

The point being just because a cars engine has a greater cubic capacity doesn't arbitrarily mean it's going to be more or less fuel efficient.