round town mpg on derv?

[zsserbia]

Now that's more like it! Still, is it possible that SDI-s were a bit dodgy? Good think there was a cheap solution to it

[Enright]

To OptimusPrimer:
My setup isn’t much different to yours.
The previous owner fitted a decat pipe (however I’ll be replacing this with a nice pretty (but probably empty) cat before my next MoT),
Standard exhaust with a Powerflow backbox,
SDi’s,
Conical air filter,
Boost set to 19psi max.
I’ve not had a remap.

Depending on how brave I am with “fuel-light roulette”, I can get up to £74 in at £1.37 per litre, which works out at 11.88gallons.
From that I usually manage between 460 and 500 miles, or 38.7 to 42.1mpg, although on occasion I’ve achieved 525 which is 44.2mpg (mind you, I’m not sure the stress was worth it)!
My commute is 22 miles each way per day, about half urban and half motorway. On the motorway I aim to maintain 80.
I’ve found on a couple of previous ZR TD’s that SDi’s usually cost you about 3mpg overall.
From figures available for Mk2 ZS TD’s on AutoTrader, the official numbers are as follows: Urban 36.2mpg, Extra Urban 65.7mpg, Combined 50.5mpg.
I don’t think I’ve ever seen as low as the lowest number, but then the other 2 just seem to be fantasy if you want to enjoy your driving at all.
I’m pretty sure that turning down your boost won’t help your economy as it makes no difference to the amount of fuel injected – the more air you get in there, the cleaner the burn will be, so conversely turning boost down just means you’ll get more un-burnt fuel (in the form of smoke) out the back.
As proof: you’ll usually see TD’s smoking the worst as the driver puts their foot down before the turbo spools up. Once they start to breathe properly they’re pretty clean.

As for “biting the bullet” about brimming it, what’s the logic? You’re going to use the fuel anyway, and there’s precious little difference between lugging it around for slightly longer as there is running backwards and forwards making 7 times as many trips to the petrol station. If anything you’re probably better off putting it in sooner rather than later as fuel prices almost always go up, so the earlier you buy in bulk, the cheaper you get it. Factor in time spent and wastage resulting from splashes, along with the ability to make a far more accurate average fuel consumption calculation, and it ought to be a no-brainer.

[C13URD]

Well after brimming mine again today & working out the mpg the SDi's are coming out on Monday & will be for sale....

[Enright]

Did you get 40 again? If it's not already had a remap, having one done might rein in the fuel that's going through them a bit and up your economy, so giving you the best of both worlds.

[optimusprimer]

Originally Posted by Enright

As for “biting the bullet” about brimming it, what’s the logic? .

I can't afford to spend £70 in one go, simple as that