C5 Tales from the Electronic Side

[jeremyC5]

Only fuel

Is that because it not "what you know", so the saying goes ?

[MULLEY]

Erm no I think you've misconstrued what i meant, there is no racetrack, if you know what i mean

[jeremyC5]

Got it
I had a Volvo V70 D5 '06 plate recently, and tested that on our local racetrack, they really DO do 140mph top speed !!
Got rid of it sharpish though, since these more modern Volvos are not for pottering around town in, they get their particulate filter clogged up very quickly, and if you don't then give them a good thrashing they then go into limp mode, if you get to that stage you have to pay the volvo dealer something like £300 to clean it out and reset the computer.

[MULLEY]

Yeah, modern high performance diesels are quite unlike an XUD engine'd one in the BX & make the Hdi one's seem pathetic peformance wise. I test drove a 330d which had the 3 litre, six cylinder twin turbo diesel engine, with the lower power of only 230 approx bhp, it went like a bat out of hell, i was really tempted, but really needed something that was going to do more than 30mpg in the real world, haha, did sound nice & it was soo easy to drive, why bother with petrol tbh??

[jeremyC5]

My 1.6 C5 is doing 49.5mpg on a journey, and drops to between 40 -44 mpg around town as an average between the two.

Does anyone how what the 3.0 ltr version of the C5 does to the gallon ?
I am tempted, they look like they are top spec. being only autos with walnut dash, etc,etc.
I guess they are also costly for the tax ?

[MULLEY]

I'm surprised the 1.6 isn't doing 50mpg on a journey, my last tank averaged 48mpg, so not too bad for a large car. No idea about the fuel consumption on the 3litre hdi, i did google it & the only thing it came up with was about 39mpg average, so i'd expect high 20's to low 30's in the real world. On a run, i'd expect low 40's?

[Tim Leech]

Smaller engine in big car doesnt not always make for super economy as you need to work it hard to get it to move!

[MULLEY]

I thought the 1.6hdi had more torque than the older 2 litre 8 valve? so assumed as the bhp was the same, that's why its more economical. I've heard great reports about fords 1litre ecoboost engine, however, on paper it looks very economical, however i've heard plenty of reports that it only does mid 30's to the gallon rather than the claimed 60mpg, but then again it is a petrol

[electrokid]

The drivers used for mpg tests are specially bred with very weak right feet

Many moons ago - had a 1.0 Metro partly as it was a step up from the mini and partly because the advertising suggested 70+ mpg. When it was still fairly new - probably 20K on the clock, I drove to join some friends on holiday in Exmouth and I had all day to do the journey so I took the pretty route - Dorchester / Jurassic coast etc and I took my time - probably close to the 56mph that seems to be the favourite speed for manufacturers to quote the mpg, and driving very gently. When I got to Exmouth I had significantly more than half a tank left - fag packet calculations suggested 76 mpg !

The journey home was quite a bit shorter - shortest route / motorway - and in convoy with a mate with a faster car and pushing most of the way - had to pull off 20 miles from home because I was running on fumes - so by definition the mpg this time was less than half the outward journey. It typically returned low 30s mpg.

Edit - both outward and return journeys started with a full tank.

[Tinkley]

One good way of getting good consumption if you want it, is to wear softish shoes. If I wear plimsolls I can really 'feel' the accelerator pedal (more like you hand does on a bike throttle). If you want the converse try driving in wellies!. The real trick is moderate acceleration and keeping corner speed high.

Note how relatively soft the 'shoes' of the race drivers are - for control and feel even though they are caning the motors, they still need feel especially in the wet.

[MULLEY]

I find coming off the throttle early rather than braking reduces fuel consumption, any form of braking means having to accelerate which wastes fuel. High corner speeds also, much to my wife's annoyance, i usually say well i'm in a 60 zone & didn't go round the corner over 60

I've also heard some interesting reports on some modern cars having better fuel economy when the engine is under load, the technique is a pumping motion of the throttle, which i've tried, but it felt too weird & was annoying to do, so didn't really explore that avenue any further. I may try again if its £2 a litre for diesel

Another technique is to once you are upto a specific speed, gently ease back on the throttle & quite often the car will stay at the required speed with less throttle & hopefully less fuell being injected into the cylinders??

A reduction in overall speed greatly helps with fuel economy, especially on longer runs, it's amazing how a drop from 70 to 60 makes most cars quite a bit more economical. The reduction in speed is phsycologicaly difficult to deal with, i was always ok with it in my TXD as the speedo over read by 10%, so the brain sees the speedo doing 70, when i was infact only doing 63, it never seemed that much slower tbh. I've not done this in the C5 yet as i found its soo quiet in comparision to the TXD, that higher speeds aren't noisy at all, infact slower speeds appear to be worse?? work that one out if you will, haha....

I'm reasonably happy with the economy i'm getting in the C5, yes i wish it was more, but for what i paid & the old technology it now is, if i can get high 40's, thats not bad really. Go back 20 years, & the equivalent granada etc would have struggled to get 25mpg.

[mds141]

My driving instructor told me to imagine there's an egg under your accelerator pedal and to press the pedal in a manner, so as not to break the egg.

[MULLEY]

Sooooo boring

[mat_fenwick]

I'd boil the egg first.

[mds141]