993 Average fuel consumption

[davidcross]

Still learning that characteristics of my 993 but have noticed MPG seems low. Whilst I'm not overly fussed I've managed to get it from 11.5 up to 17 mpg according to the trip computer. Seem a little low?? The 11.5 bit I guess is to do with the car being started to keep things moving before sale and a few test drives.

 

[davidcross]

well im no where close to those stats at present although it did get better at the weekend. Im not flooring it every five minutes so any likely explanation? there are no smelly petrol leaks as far as i can tell

 

[Andy B Aces High]

Mine averages between 25 to 30 mpg most of the time. Even managed this on a trip through the traffic to Hendon last weekend.

Would suggest that if you are only getting 11 mpg then you are either driving her really hard all the time or there is a problem. This may only be the fuel computer, but could be something more serious and would be worth getting checked because if it is dumping too much fuel in then this can lead to bore washing and a damaged piston or barrel.

Just to check, how are you using the fuel computer, silly question but it is on "average" and are you taking the reading over a couple of days of varied driving ?

 

[verysideways]

Ok - all mine were daily drivers and i drove them like i stole them half the time (sorry) and i got (average):

993 C4S : 21mpg
993 C2 : 24mpg
993 TT : 14mpg stock, 12mpg with RS Tuning stage 1
993 C2 : 22mpg

However - i wouldn't necessarily trust the computer. Have you actually got the calculator out and checked how many litres to how many miles from brim full to brim full?

 

[davidcross]

ive not yet been anal enough to check whats going in the tank and how many miles its producing. I zero"d the trip at the weekend incase it was stuck and i got the current average up to 17. i do a fair amount of dropping her down 2 gears and going for it but not constantly. it doesnt stink of fuel or isnt leaving any fuel patches anywhere. Anyone locally to Brentwood where i live i can hook up with for a general comparrison with may help? maybe the computer is palying up. best i monitor it over the next week maybe. my 997s only ever managed 20mpg with my driving style and typical joyrneys i done

 

[Mike M]

993 C2 no vario 22mpg driven fairly hard

 

[davidcross]

Well mine is a c4 and 285 bhp but is it varioram?? not sure i know the difference

 

[cobalt911]

Varioram has an alloy lump on the top, sometimes stamped with 'varioram'....

I get between 17 and 18mpg locally (giving and not giving the beans) and on long runs up to 28mpg. The short stuff is the killer when the engine is cold and all that...

 

[davidcross]

Alloy lump on the top of what?

 

[Andy B Aces High]

The inlet manifold assembly on top of the engine on the Varioram is silver coloured and manufactured from aluminium, on Non-Varioram this is a black plastic moulding. They both have six tubular shape pieces that join the top of the engine cylinder heads. Either way whatever you have this will not affect the fuel consumption too much.

If you don't have a heavy smell of fuel then it sounds more like the fuel computer is at fault.

I noticed on another one of your posts that you have only recently bought your car from Paul Stephens, if you are concerned cant you get him to take a look at it ?

 

[p27549]

I am averaging 23 MPG and thats with 352 BHP supercharged. Approx 340 to a tank based on 65 litres.

 

[clyde]

David, I take it that when you say you've re-set the "trip" you mean the OBC mpg figure? If not (or even if you have) I would re-set it after the engine is warm and this will give you a better idea of consumption taking the cold engine out of the equation. The 993's engine can take a while to warm up, especially in the cold weather we've been experiencing.

I get about 17 mpg on normal daily use but this is all A roads, if I go anywhere on a motorway this shoots up to about 23 or so. If I re-set the OBC on the motorway I can get 28 or so cruising at a good speed.

I also had an issue periodically a while back with the OBC fuel consumption figure going up like a stop clock at about .1 a second (I have a left hooker, so the read-out is in l/100km - the higher the worse it is). It would stop if I re-set it or stopped the engine and re-started.

 

[davidcross]

Well I used it last night and it's up to 17.2 mpg which is round town and A road driving so from what u have said this is normal. The weekend should give me a chance to take her for a run.
All my readings are from the OBC. I've not noticed an aluminium plate on the top of the engine so I guess mine is 285 bhp but not varioram. Tks everyone

 

[dommorton]

272bhp if non-vario []

 

[davidcross]

i keep posting this bit as i spotted on the web last week an article stating that a 1995 c4 is 285 bhp but not a c2. im desperately trying to find it again!!!!!

 

[cristel993]

Hi David,

I've posted a response to your bhp thread to show you the visual differences between a Varioram and non-Varioram engine:

http://www.porscheclubgbforum.com/tm.asp?m=536106&mpage=1&key=򂺡

Varioram engine - 285bhp:

http://s798.photobucket.com/albums/yy270/cyruspower/Cristel993/?action=view&current=P1030352.jpg

Non Varioram engine - 272bhp:

http://www.scaleautoworks.com/993engine3.jpg

Sam

 

[craig2105]

David - it sounds to me like you are looking at the average consumption figure and it's going up only gradually as it's measured over the mileage since it was last reset (which I think is limited to 1000 miles if not manually reset?) So as you are driving more economically than it has measured over that period, the figure is increasing slowly. I don't have my 993 any more so I'm going from memory, but I think there's a way to manually reset the average consumption reading to start again - check your manual. Then you'll see what it's actually doing in your hands. Mine always hovered around 23mpg in general use, but once I'd stopped using it every day, it dropped to about 17 to 18 because these were only "fun miles"!

Enjoy! []

Jealous...[]

 

[davidcross]

tks Craig, i have zero"d the computer so ill monitor it. im sure in time ill get to early 20"s eventually. For the recoed im really enjoying the car and not pineing for my 997.

 

[cristel993]

Hi Maurice,

Many thanks for posting the link the Varioram information. I've noticed the difference in power delivery between my current Varioram 993 and my previous non-Varioram 993.

As well as increased pull from lower down and what feels like a more linear power delivery, I think the engine sounds slightly different too.

I wonder if anyone else would agree that the two engines sound slightly different?

I've also noticed that the exhaust tail pipes are a different shape. Does the exhaust system differ in any other ways between the two 3.6l 993 engines?

Sam

 

[Porker993]

To answer the original post - I get around 21 mpg 50/50 mixed town and A road driving on the daily commute. This increases to 28 on a long motorway trip with no stop start traffic. 17 is definitely a bit low.

I heard last week that the V-ram cars have a different gearbox, with slightly taller ratios, due to Swiss noise regulations ?

A V-Ram owner driving my early non V-Ram car found it noticeably higher geared.

Maurice can no doubt confirm ?