Has someone sent this to Lotus?

[Lichtgestalt]

James May calling on all engineers to build a light car... I reckon the Elise isn't far off if you make it a bit more user-friendly

http://www.telegraph.co.uk/motoring/main.jhtml?xml...

[RobM77]

I've always been amazed why if my Elise is possible to make, and does 45mpg, has 163g/km of CO2 and 0-60 in under five seconds; why it isn't possible to make an ordinary four seater car with the same economy figures but less performance - just trade the weight of the seats and sound deadening for the performance.

[LivinLaVidaLotus]

Your Rover Elise doesn't have 163g CO2/km though - it's Euro III, which was tested differently to Euro IV cars - I think someone on here already pointed that out, Euro III gave 30s to warm up before being tested, which makes a difference.

There is no excuse though for seriously lardy small cars though.

Edited by LivinLaVidaLotus on Thursday 10th July 17:24

[Scuffers]

LivinLaVidaLotus said:

Your Rover Elise doesn't have 163g CO2/km though - it's Euro III, which was tested differently to Euro IV cars - I think someone on here already pointed that out, Euro III gave 30s to warm up before being tested, which makes a difference.

There is no excuse though for seriously lardy small cars though.

Edited by LivinLaVidaLotus on Thursday 10th July 17:24

err you mean EU2 and EU3, not 3&4 but essetially you are correct....

[LivinLaVidaLotus]

What can I say, it's nearly Friday, lol.

[bordseye]

RobM77 said:

I've always been amazed why if my Elise is possible to make, and does 45mpg, has 163g/km of CO2 and 0-60 in under five seconds; why it isn't possible to make an ordinary four seater car with the same economy figures but less performance - just trade the weight of the seats and sound deadening for the performance.

dont understand. there are lots of small 4 seaters with better economy - look at the small citroens/peugeot or the toyota aygo. much the same weight as an elise, 80bhp engine and you can expect 60mpg if you dont thrash the nuts off it.

but just wait. I reckon we've come to a tipping point where it will sell cars if they are economical on fuel - and weight is one way of doing this. you'll soon see 4 seater family cars for sale that are capable of a real life 80mpg or even 100. economy has never really mattered before which is why car engines are twice the capacity they were when I was a kid and the cars they power are blaoted to 1.25 tonnes or more. and you get horrors like the suv.

[RobM77]

bordseye said:

RobM77 said:

I've always been amazed why if my Elise is possible to make, and does 45mpg, has 163g/km of CO2 and 0-60 in under five seconds; why it isn't possible to make an ordinary four seater car with the same economy figures but less performance - just trade the weight of the seats and sound deadening for the performance.

dont understand. there are lots of small 4 seaters with better economy - look at the small citroens/peugeot or the toyota aygo. much the same weight as an elise, 80bhp engine and you can expect 60mpg if you dont thrash the nuts off it.

but just wait. I reckon we've come to a tipping point where it will sell cars if they are economical on fuel - and weight is one way of doing this. you'll soon see 4 seater family cars for sale that are capable of a real life 80mpg or even 100. economy has never really mattered before which is why car engines are twice the capacity they were when I was a kid and the cars they power are blaoted to 1.25 tonnes or more. and you get horrors like the suv.

Sorry, that didn't come out right. To rephrase, imagine putting a 1.2 litre engine in my Elise. It'd do 0-60 in about 7 seconds and return about 80mpg. If you added sound deadening etc it'd probably only knock 10% off both those values.

[kambites]

The K-series Elise's CO2 output may have been tested differently to the 'yota engined cars, but in my experience the figures are born out by the difference in fuel economy. With me driving, a 111S uses about 20% less fuel than a 111R.

I've always wondered how Lotus got the Elise's (any Elise) economy so low though. There are other cars which weigh far more and have a significantly greater CDa using exactly the same engines which give similar or better fuel economy.

Edited by kambites on Friday 11th July 08:44

[Scuffers]

kambites said:

I've always wondered how Lotus got the Elise's (any Elise) economy so low though. There are other cars which weigh far more and have a significantly greater CDa using exactly the same engines which give similar or better fuel economy.

one word.... Gearing....

actually, it's not just that, but that makes a huge difference to the official test cycle,

things that affect the test cycle are:

1) weight - the loads apllied to the wheels are calcualted from the weight of the car (along with)
2) Rolling resistance - again the loads applied adjusted for this.
3) CDa - as above
4) overall gear ratio's - test cycle defines which gear is used at what point

Now, the Elise/Exige have really stty CDa figures (relative to mainstream stuff), and fitting them with A048R tyres does not exactly help, then combine this with (relatively) low gear ratio's, there is your reasons.

the Rover engined S2's without the CR box, on std tyres without bit's hanging off them were always going to do better on these tests, I also suspect Lotus certified these in-house (and thus spent an inordiate amount of time in the ECU to achive the low results).

[peter_england99]

kambites said:

The K-series Elise's CO2 output may have been tested differently to the 'yota engined cars, but in my experience the figures are born out by the difference in fuel economy. With me driving, a 111S uses about 20% less fuel than a 111R.

I've always wondered how Lotus got the Elise's (any Elise) economy so low though. There are other cars which weigh far more and have a significantly greater CDa using exactly the same engines which give similar or better fuel economy.

The Elise always had a better MPG than the MGF-MG TF using the same engine. What cars are you referring to with better MPG with the same engine as the Elise?

Regards,
Peter.

[Tuna]

Surely the point is that the Elise chassis is completely over engineered from the point of view of a small light, mass produced car? Huge torsional rigidity isn't needed in a small town car, nor is the complexity of a chassis that's independent of the body panels that it supports. The Elise chassis really isn't suitable for mass production on the scale that you'd need for a worthwhile eco-box.

The biggest issue with getting small cars to be light is meeting all of the crash and safety legislation. Otherwise we could go back to the likes of the original Mini, which would have sky high mpg if it were made with modern materials and engine technology.

[kambites]

peter_england99 said:

The Elise always had a better MPG than the MGF-MG TF using the same engine. What cars are you referring to with better MPG with the same engine as the Elise?

I was thinking of things like the Rover 200 1.8 16v. 1.1 tonnes, massively greater frontal area, and 40mpg - the same as the Elise with that engine.

And from a Toyota front, the Corrola T-sport does 34mpg on the combined cycle despite weighing 1300kg!

Maybe Lotus are more honest with their figures (I can get the claimed 41mpg from my 111S without going near a motorway). Dunno.

Edited by kambites on Friday 11th July 10:00

[LivinLaVidaLotus]

I can get 34+ mpg from my 111R, regularly get 32, could get a lot more if I tried. As has been said though, it's not just weight that plays a part.

[kambites]

LivinLaVidaLotus said:

I can get 34+ mpg from my 111R, regularly get 32, could get a lot more if I tried. As has been said though, it's not just weight that plays a part.

That's what I mean though. The Corrola is 1.5 times the weight and has 1.5 times the drag yet manages similar efficiency. 34mpg is shocking for such a small, light, car. The 111R should be returning 40mpg without even trying.

Edited by kambites on Friday 11th July 10:05

[Fidgits]

LivinLaVidaLotus said:

I can get 34+ mpg from my 111R, regularly get 32, could get a lot more if I tried. As has been said though, it's not just weight that plays a part.

I have managed to get 40MPG from mine quite easily on longer runs..

[kambites]

Fidgits said:

LivinLaVidaLotus said:

I can get 34+ mpg from my 111R, regularly get 32, could get a lot more if I tried. As has been said though, it's not just weight that plays a part.

I have managed to get 40MPG from mine quite easily on longer runs..

I can get 50mpg from mine (111S) on long runs but that's not the point, I'm sure a Corrola T-sport will easily do 40mpg on runs too.

[cjm]

Tuna said:

Surely the point is that the Elise chassis is completely over engineered from the point of view of a small light, mass produced car? Huge torsional rigidity isn't needed in a small town car, nor is the complexity of a chassis that's independent of the body panels that it supports.

Pretty sure the elise doesnt really have a huge torsional rigidity figure next to a new 3 series or small hatch.

[kambites]

cjm said:

Tuna said:

Surely the point is that the Elise chassis is completely over engineered from the point of view of a small light, mass produced car? Huge torsional rigidity isn't needed in a small town car, nor is the complexity of a chassis that's independent of the body panels that it supports.

Pretty sure the elise doesnt really have a huge torsional rigidity figure next to a new 3 series or small hatch.

Depends on how you measure it. From a "stiffness of the car" point of view, what matters is the ratio of torsional rigidity to weight (because it's the momentum of the car that's trying to twist the chassis). It's probably less stiff in absolute terms though, yes.

[Fidgits]

kambites said:

Fidgits said:

LivinLaVidaLotus said:

I can get 34+ mpg from my 111R, regularly get 32, could get a lot more if I tried. As has been said though, it's not just weight that plays a part.

I have managed to get 40MPG from mine quite easily on longer runs..

I can get 50mpg from mine (111S) on long runs but that's not the point, I'm sure a Corrola T-sport will easily do 40mpg on runs too.

not a chance mate... I know a guy that owned one... he was lucky to get above 35MPG! he hated it...

dont forget that 6th in the R is quite short, your over 3k at 70mph...

[kambites]

Fidgits said:

not a chance mate... I know a guy that owned one... he was lucky to get above 35MPG! he hated it...

dont forget that 6th in the R is quite short, your over 3k at 70mph...

My average since buying the car (without driving on motorways more than once a month) is now 39mpg and I don't drive particularly gently. Last time I had it on the motorway I got 49mpg including driving to and from the motorway.

Got a broken Lambda sensor at the moment though, so it's down to about 35mpg


ETA: to be fair I do tend to drive quite slowly on the motorway - the noise drives me mad above about 70mph.

Edited by kambites on Friday 11th July 10:18