Activa Fuel Economy - Very Happy!

Post by **CitroJim** » 16 May 2007, 16:22

Yes, I know, a subject that has been covered a million times before

I just have to share this though. Today I have done a round trip to Dover along the M1, M25, A2, M2 and A2. 290 miles all round in my Activa.

Apart from the normal M1, M2 and A2 roadworks and a holdup at the QEII bridge, I was running at the prevailing speed limit and not hanging around.

MPG for the trip? 39

This was my first decent long trip in it.

Very pleased indeed. I just wish it would do that during local pottering around

The car performed absolutely brilliantly and never missed a beat

Xaccers · Post by **Xaccers** » 16 May 2007, 16:24

I'll just sit here and try not to be jealous of your mpg *sulk*

Post by **CitroJim** » 16 May 2007, 16:35

Xac wrote:I'll just sit here and try not to be jealous of your mpg *sulk*

But on the flip-side, running around MK, the cars normal habitat, I'm lucky to get mid 20s

Today was exceptional and I did seriously try for economy whithout sacrificing progress. Yours under similar conditions would easily have topped 50

lolingram · Post by **lolingram** » 21 May 2007, 10:42

Is your Activa the Turbo petrol version?

just have to share this though. Today I have done a round trip to Dover along the M1, M25, A2, M2 and A2. 290 miles all round in my Activa.

Apart from the normal M1, M2 and A2 roadworks and a holdup at the QEII bridge, I was running at the prevailing speed limit and not hanging around.

MPG for the trip? 39

Post by **CitroJim** » 21 May 2007, 10:58

lolingram wrote:Is your Activa the Turbo petrol version?

Yes, the XU10J2CTE engine. The only engine the Activa ever came with in the UK

. That was why I was so happy with 39 MPG. I'd

if it were a diesel and returned economy like that

LeeDJC · Post by **LeeDJC** » 21 May 2007, 13:16

Congrats Jim, 39 is very good

I wish I could get that from mine! If I could, then I wouldn't be selling it! I was just thinking however, that as it's possible to increase the boost with a boost controller, is it possible to use a controller to REDUCE the boost and therefore increase the economy? It could be turned back up now and again for a bit of fun now and again

As you may have seen, mine is on fleabay. No-one has bid on it yet, but I'm getting increasingly twitchy having it on there!

Sorry to hijack your thread!

Post by **CitroJim** » 21 May 2007, 13:39

No worries Lee

Do bear in mind though the 39 was achived on a run. Normal running around is mid-20s

I like your idea of variable boost to suit prevailing conditions but it may not work to improve economy. If my understanding is correct then best fuel economy comes from having a high compression ratio but because turbocharging increases the effective compression ratio under boost the base compression ratio of the engine has to be low and hence it runs inefficiently off-boost

I may be talking a load of muppetry here but I find mine runs most economically if you keep it on gentle boost. The problem is that the engine has so much low-down grunt there is a tempation to chug it along like a diesel at low revs thinking this will result in best economy. In fact, the opposite is true. keep it revving freely and on boost. This keeps the Volumetric Efficiency high and keeps the effective compression ratio up where it needs to be for optimum fuel consumption.

Best of luck with selling your Activa Lee, and sorry to see you leaving the Activa fold. Had I not had mine, I would have jumped at it. Yours is in my favourite Activa colour. If only colours could be swapped...

LeeDJC · Post by **LeeDJC** » 21 May 2007, 19:54

Thanks Jim. I didn't think it'd be quite as easy as to just reduce the boost. Oh well!

You may have seen my "For Sale" post has now been updated. I have decided to keep it now. After cleaning the car up and seeing how good the car looked (especially in the sun) and taking it out for a good couple of blasts

, I have decided that it wouldn't be in anybodys best interest (particularly mine) to get rid. I've only had it a couple of months, but I already feel attached to the damn thing! lol

It's needed as a run-around for the better half at the minute while we sort her mini out, but once thats done it'll probably have to go into the garage for a little while until we're sorted. At least that'll give me time to go around it and get those little niggles sorted.

Again, sorry for the hijack!

Post by **CitroJim** » 21 May 2007, 20:31

Excellent Lee

I'm very pleased you're keeping the Activa and yours looks like one well worth preserving. Better than some baseball wearing chav buying it for its engine

One day an Activa will find its rightful place among the modern classics.

I know what you mean about getting attached to them. Usually after a lot of blood sweat and tears have been shed over them

Keeping the revs up and a featherlight touch on the

pedal goes a long way to keeping the fuel economy tolerable. Just occasionally you need to really give it some to appreciate just what an Activa is all about and after being economical you can give yourself a treat

This thread has got me seriously thinking about possible economy tweaks. The first one, rather major I admit, would be to slot a 2.1TD in it. It should be relatively straightforward given that much of the running gear (gearbox etc) is the same but I've not heard of it being done.

Does anyone know if it has?

LeeDJC · Post by **LeeDJC** » 21 May 2007, 20:38

citrojim wrote:
Does anyone know if it has?

I'm sure I've heard of someone converting one to a 2.1TD. Possible over on the ActivaNet forums.

I don't know how much the 2.1TDs go for, but I'm sure if you sell off the CT, it'd easily fund one, probably with some cash left over!