Big engines are more economical?

[wemorgan]

I am prepared to throw down the gauntlet and challenge any car that's greater than 2L in capacity to better the mpg of my 800cc CDI.

Whilst not better than yours, I highly rate the Honda Civic 2.2 CTDI for a decent balance of efficiency, performance and price.

I'm averaging ~52mpg in my real world driving, but I once achieved ~70mpg on a 25 mile door-to-door run. Some drivers report as much as ~80mpg on a tank-to-tank.

 

[Sp!ke]

This week I am driving a little gentler than I normally do to see what I get out of it now the engine has a fair amount of miles under its belt. (always a good measure of engine health)

My 30 mile commute takes up to an hour and a half so its stop start for much of the way and far removed from ideal conditions and yet it looks like I will get very close to 550 miles out of the 30 litre tank. (83.3mpg)

Driving normally (flat out everywhere), I still get 480 miles from 30 litres. (72mpg)

In ideal conditions, I'm sure it would better 100mpg.

These figures are brim to brim so no OBD estimation involved. I'm not aware of any other conventional engined car that betters this in real world driving despite some manufacturer claims. I'd certainly be interested to learn if there is something as I'm wondering what to get next should I opt not to pay the balloon final payment.

 

[wemorgan]

These figures are brim to brim so no OBD estimation involved. I'm not aware of any other conventional engined car that betters this in real world driving despite some manufacturer claims. I'd certainly be interested to learn if there is something as I'm wondering what to get next should I opt not to pay the balloon final payment.

~15 years ago Audi made the A2 1.2TDi that averaged 80mpg. Many owners report >110mpg on tank-to-tank. But that's of course no longer available as a new car, so not an option for you, but goes to show what can be done with conventional engined cars if there's a desire.

 

[John]

~15 years ago Audi made the A2 1.2TDi that averaged 80mpg. Many owners report >110mpg on tank-to-tank. But that's of course no longer available as a new car, so not an option for you, but goes to show what can be done with conventional engined cars if there's a desire.

I remember when they came out - incredible figures back then...

 

[MancMike]

I will get very close to 550 miles out of the 30 litre tank. (83.3mpg)

What is this little sipper you speak of?

 

[Sp!ke]

What is this little sipper you speak of?

Smart CDi.

 

[Sp!ke]

~15 years ago Audi made the A2 1.2TDi that averaged 80mpg. Many owners report >110mpg on tank-to-tank. But that's of course no longer available as a new car, so not an option for you, but goes to show what can be done with conventional engined cars if there's a desire.

That is impressive if indeed it is attainable.

The numbers on Fuelly don't match your observations though.

 

[E270 Owner]

Whilst not better than yours, I highly rate the Honda Civic 2.2 CTDI for a decent balance of efficiency, performance and price.

I'm averaging ~52mpg in my real world driving, but I once achieved ~70mpg on a 25 mile door-to-door run. Some drivers report as much as ~80mpg on a tank-to-tank.

We have a Civic 2.2CTDI pool car with @ 190,000 miles on it, 70mpg is normal with 45 running around London suburbs.

Marvellous engine, ultra reliable.

That said a Vectra C 1.9 8v estate (Fiat group engine) with a remap was giving us @ 70+mpg on continental trips loaded up












.

 

[wemorgan]

That is impressive if indeed it is attainable.

The numbers on Fuelly don't match your observations though.

Spritmonitor.de often has a larger database IMHO

Overview: Audi - A2 3L - Spritmonitor.de

 

[Bellow]

As such it's no surprise that when driven in real world conditions, the achieved fuel consumption is often at significant variance with the "standard test" figures.

I suspect that manufacturers worry less about demonstrating good economy in the standard EU testing regime for larger engined high performance vehicles, and therefore the real world fuel consumption is probably closer to the published numbers.

That is close to it I suspect. Allied to..the snail's pace acceleration the tests employ. The small engine will do well but when in real conditions deteriorate significantly. The large engine will do less well in the test but the gap to its real condition consumption will be narrower as a consequence.

~15 years ago Audi made the A2 1.2TDi that averaged 80mpg. Many owners report >110mpg on tank-to-tank. But that's of course no longer available as a new car, so not an option for you, but goes to show what can be done with conventional engined cars if there's a desire.

That thing was a freak. So focused was it that if the crank bearings ran a new block was required. And we all know the rumour of the rumour that led to it being built in the first place.

 

[Sp!ke]

That thing was a freak. So focused was it that if the crank bearings ran a new block was required. And we all know the rumour of the rumour that led to it being built in the first place.

I dont know the rumour.

 

[Bellow]

The Audi was what the Germans obsessively referred to as a 3litre car, ie 100km/3l of fuel. Rumour has it that VAG heard a rumour that Renault were building a 3 litre Clio and couldn't bear to be beaten so went all out on the Audi A2. Renault did produce a 3 litre Clio. With a 3 litre V6!

 

[wemorgan]

That thing was a freak. So focused was it that if the crank bearings ran a new block was required. And we all know the rumour of the rumour that led to it being built in the first place.

The more mainstream 1.4TDi wasn't too shabby either. Spritmonitor shows some users with>70mpg average.

Overview: Audi - A2 - Spritmonitor.de

ps. my old A2 1.4TDi is for sale if anyone is interested

 

[st13phil]

That is close to it I suspect.

A few years ago, while in conversation with someone well placed to know these things, I was told that one of the major German manufacturer's used engine ECU's that "recognised" the EU test cycle and adjusted fuelling parameters accordingly to ensure favourable results. I was also told that the manufacturer concerned "didn't produce the car you drive" (at the time I owned a C220CDI).

 

[Deleted member 65149]

This all proves that I've been wrong for a very long time. I thought that everyone knew by now that manufacturers' consumption figures were only of any use in comparing very similar cars, and certainly not an indicator of real world figures. Apart from anything else, everybody's right feet are different so even completely identical cars will result in a significant variance. Add in the high number of other variants from total weight carried to journey characteristics and it becomes obvious (well, it does to me) that published figures are totally irrelevant.

 

[Bellow]

The more mainstream 1.4TDi wasn't too shabby either. Spritmonitor shows some users with>70mpg average.

Indeed - and I've always admired the efficiency inherent in the A2 concept. Just that the 3 litre was too extreme, a result of chasing a headline figure over all else.

ps. my old A2 1.4TDi is for sale if anyone is interested

In selling - we call that BIG. Before I Go...did I mention?.....
Nice one!

A few years ago, while in conversation with someone well placed to know these things, I was told that one of the major German manufacturer's used engine ECU's that "recognised" the EU test cycle and adjusted fuelling parameters accordingly to ensure favourable results. I was also told that the manufacturer concerned "didn't produce the car you drive" (at the time I owned a C220CDI).

That wouldn't surprise me at all. Another little trick I've heard they employ is anything from a lower powered model that helps the aero, eg, reduced size radiator air entry aperture. Never mind that it would overheat in real life use, for the test - it works a treat.

 

[Sp!ke]

I thought the tests were on a bench?

 

[sallison1504]

This all proves that I've been wrong for a very long time. I thought that everyone knew by now that manufacturers' consumption figures were only of any use in comparing very similar cars, and certainly not an indicator of real world figures. Apart from anything else, everybody's right feet are different so even completely identical cars will result in a significant variance. Add in the high number of other variants from total weight carried to journey characteristics and it becomes obvious (well, it does to me) that published figures are totally irrelevant.

The representative MPG figures are only to assist the prospective purchaser in choosing an engine from that particular model, as in just one model, the engine will be the only major variant that affects fuel economy, thus helping the purchaser make an informed decision on the engine they choose based on their requirements and long term fuel budget.

Either way it's all a big con.

 

[V12]

My wife's 1.0 petrol car achieves 50mpg every single tank without fail. It can do 50mpg in almost standstill traffic or at motorway speeds.

My S320cdi which is 2 and a half times heavier and more than 3 times more powerful can also achieve 50mpg on the motorway but sat in traffic it'll drop to 25mpg.

I think this demonstrates different vehicles for different jobs.

 

[m2287]

My wife's 1.0 petrol car achieves 50mpg every single tank without fail. It can do 50mpg in almost standstill traffic or at motorway speeds.

My S320cdi which is 2 and a half times heavier and more than 3 times more powerful can also achieve 50mpg on the motorway but sat in traffic it'll drop to 25mpg.

I think this demonstrates different vehicles for different jobs.

Got an S320 Cdi recently and I have really noticed the mpg is amazing on the motorway but so so poor in stop start traffic! It was almost as bad as my AMG!