15 MPG and Australia

[pauljmcnulty]

Ok, they aren't actually related but both cropped up today. [&:]

I had what's suspected to be an ARB failure of some kind in November. Being laid up with Swine Flu, and there being a lot of snow and stuff, and there being no point getting the car to RPM before they all went off for Christmas, the old girl has sat on the drive unused for over a month now. Well, today it finally got driven over, so hopefully it'll be back in time for the Rutland meet. Failing that, the Cotswold Rally, as my "professional parker" hi-viz Club vest is in the boot.

I had to fill up before I left, a bit of a shock at £1.32 per litre but hey, we Porsche drivers can afford it [&o]. Working it out, the car only did 15 MPG last tankful. Combined with the very wierd feeling that the car was almost "holding" on slight inclines, instead of rolling forward or back, I'm guessing the brakes are binding, so probably at least two caliper re-furbs on the bill.

Whilst I was there, RPM have a Turbo they're breaking. Apparently it was bought off e-bay in order to be shipped out to Australia. It's the rustiest car I've ever seen, I actually stepped out from under it when I saw what was holding it on the lift! Wasn't there a chap looking for a car here a few months ago? If it was you, sorry to see that you were so badly ripped off by the seller, but at least you got a decent amount back all things considered, and the car will help keep a few others going! [&o]

 

[Suffolk944]

That's a mpg that would make even us Turbo owners blanche somewhat ! Mines going in for its new turbo plus possible bodywork at long last this Saturday so again it will hopefully be back in time for the revised Rutland date, which looks like it will be 27th Feb...

 

[VanhireBoys]

I had bad MPG in mine for a while.. It turned out to be the Lambda Sensor in the exhaust was duff....! The management goes into "open loop" control.. The giveaway was the emissions...

This might be no good to you as we all know mine is a US Turbo .. It might be worth a look anyway....!

Are all S2's fitted with cats and lambda sensors...?

 

[zcacogp]

Paul,

I'd be interested in an MPG survey amongst S2 owners, particularly as petrol is so damned expensive these days, but 15mpg sounds bad. The worst I have seen across a tank in mine is about 16, so comparable but still bad.

Some MPG points in my S2:

- It seems to average about 27-29 (across a tank), but this is quite variable. This equates to between 350 and 400 miles to a tank, assuming that a tank is 'filled' to the first shut-off click on the filler nozzle, and 'empty' when the fuel light comes on.
- The way that the car is driven (hard or gently) doesn't make that much difference; a little, but not as much as you would expect.
- I think that the warm-up routine takes a LOT of fuel; if I do a lot of short journeys, letting the car cool each time it is stopped, the MPG drops off very rapidly.
- Cold weather can dent the MPG. I get, on average, 10% better MPG in the summer than in the winter.
- MPG may drop off quite swiftly over about 120mph and may drop even more quickly at higher speeds.
- Stop-start driving 'round town is not good for the MPG. Longer-distance runs are much better.
- Tyre pressure can have a LARGE effect on MPG. Much more than I would expect - probably up to 15 or more %.
- High-octane petrol gives better MPG, but costs a smidge more. The two factors cancel each other out, leading to a very similar £/mile cost, but the car does run better on the higher-octane stuff.
- The best distance I managed on a tank of juice was a little under 500 miles, equating to 32mpg. This was a fast but constant speed drive back from the Loire Valley to London; I started the car about four times between full and empty, it was very hot weather, there was very little stop-start driving and the speeds were pretty constant for most of the journey.


Oli.

 

[david924s]

I get on average over full tanks around 26/28 mpg (driving to work, stop start, round town stuff) and over 33 on long motorway trips at around normal motorway speeds. 1991 944 S2 105K miles tyre pressures 36psi all round Toyo T1Rs, Promax chip and K&N panel filter fitted no other mods.

 

[supersport]

I have just had the rear brakes done, I think at least one was binding slightly before and done an oil/filter change and the car not only feels lighter and more sprightly (although this only lasted a week or until I got used to it) but the MPG has vastly improved.

Last weekend the car did two long runs and we did it one tank, getting 427 before I chickened out and put more in. I suspect we could easily have got home, but there were no more filling stations until I got there. I think we could have done around the 460 mark. Previously we once crept up to 400 and generally got around 380.

 

[zcacogp]

Sc0tty,

Yes, as you say. In fact, I tend to keep the pressures higher, usually favouring 38psi all 'round.

Spotting low pressures is usually done by noticing the handling is all to pot, but once sorted out the MPG goes up noticeably as well.


Oli.

 

[Robin]

Paul, You might like to check your flexible fuel hoses for fuel leaks, I have recently replaced mine after a drive round France in September and used their 90E10 unleaded fuel which contains 10% Ethanol and which dissolved some of the old fuel hoses causing serious leaks. I am not sure if UK fuel contains other additives but if they do it might be the cause of your poor fuel consumption figures. Incidentally Pelican Parts in USA reccomend changing fuel hoses every 2 to 3 years because of what modern fuels contain, but I suppose they might say that as they sell fuel hoses, but it is worth checking them.

 

[DavidL]

38 seems awfully high, I know mine aren't. Don't you find it a bit well bouncy?

I had my Caterham back from a dealer (a caterham dealer I should add) and thought something was very odd as I drove home.
Checked the tyre pressures and they were 30 all round. Not to bad you think until you realise I normally run 16!!

 

[pauljmcnulty]

Paul, You might like to check your flexible fuel hoses for fuel leaks

Fuel lines were all deemed ok at last service, they are corroded and will go, but I've had that on the old Lux and you soon know it!

This is all down to the binding brakes from the caliper corrosion, unless they find an additional problem. I hadn't used the car over Christmas, but on the journey to RPM the car was able to hold itself on quite a surprising slope without the handbrake, so they are binding pretty badly. [&o]

 

[Fat Albert]

My car was due to be shipped to Aus too, but I offered slightly more to keep it here!
I get high 20s when i am on long journeys, and have got up to 380 miles from a tankful with light shoes on, normally 340 with heavier shoes

I think this time of year driving everywhere with the lights up knocks a couple of MPG off

 

[pauljmcnulty]

Updated today when the RPM boys had looked over the car. And picked themselves up off the floor laughing at it.

All four calipers need an overhaul as they are all binding now, hence the MPG. At least the back needs discs and pads, plus the front will probably need doing. New handbrake shoes, brake lines, fluid etc. Plus all the ARB bushes and the broken drop link. A replacement indicator stalk, drilling out and re-threading one fog light and a few other little bits just "while we're at it".

Being fair I knew it needed the brakes when I bought it, so 18 months isn't bad. Just a shame it comes after Christmas, with the income tax tax bill to pay next week and the insurance arriving any minute! []

 

[zcacogp]

Ouch Paul. That sounds like a hefty bill being lined up for you. I'm sorry to hear it. There is never a good time, eh?

The silver lining is that it should be a MUCH better car to drive when it's done. Binding brakes will hamper the performance, and broken droplink (and knackered bushes) will scupper the handling. It will feel like a proper Porsche again when fixed ...


Oli.

 

[pauljmcnulty]

It will feel like a proper Porsche again when fixed ...

It'll be interesting to see. The ARB problem made a noticeable difference to the handling, as you'd expect all new bushes will be lovely.

The brakes are a different thing, as I'd not thought they were bad. I guess that things that get slowly worse do pass you by, then you realise how bad it was when you get the car back. It'll certainly be different: 4 calipers overhauled, discs and pads all round, new brake lines and fluid, if it doesn't feel any better I'll be surprised! [&:]

I was adding up the estimate last night. Not bothering with powder-coating the calipers, you can't see much of them through D90s and I'm not the showy-off type who wants red or yellow, and it's quite reasonable. Still the price of a good Lux though, just for a few repairs. I keep reminding myself to listen to my own advice and remember how cheap it was to buy, no depreciation etc. [][]