Sintra 3.0 mpg

We use the car on shortish journeys mostly and the driving is a bit stop
start. At the moment wer're averaging around 18 mpg which aint good, and
that's driving quite carefully. Does that sound about right? I did read
somewhere before that if the lambda (sp??) sensor has gone that can cause
bad mpg figures, is there any way to tell if it's faulty??

Cheers, Chris

 

The oxygen sensor can be tested to check its overall integrity, as a bad
sensor won't always set a fault code. For detailed instructions follow the
link:
http://forums.delphiforums.com/cartune/messages?msg=38.1
You can sign in as a guest, which will allow you to read posts, but not
write any.

 

a tech2 link up at your local vauxhall dealer for about £10-15 will tell
you.
i have a 2.2 16v cd, get about 25-30 in your conditions.
i find the super unleaded better (97 octane?)
rather than just unleaded gives me more (30-35)
but for the price, just about works out the same as such....

we got about another 5-7mpg by changing the fuel filter

tried that?

mike

 

We use the car on shortish journeys mostly and the driving is a bit stop

To be honest that sounds about right - it's a big heavy vehicle being
powered by a 3 litre V6 engine. All depends exactly how stop start your
journeys are, but if it's a lot of short journeys (<1 mile) then I wouldn't
be at all suprised by this. Maybe a good service is in order - new air
filter, fuel filter, oil and filter change, but at the most I'd expect
22-23mpg for that sort of driving, so I wouldn't say there's much wrong with
it if I'm honest.

Peter

 

To be honest that sounds about right - it's a big heavy vehicle being

Cheers, was serviced about 1000 miles ago so should be nothing needed doing.
I don't suppose any of those addatives like slick 50 would help? I am fairly
sceptical about these wonder products

Thanks for all the replies.

Chris

 

to be honest i wouldn't want to upset the semi-synth oil or the fuel chain
at all.

mike

 

Cheers, was serviced about 1000 miles ago so should be nothing needed
doing.

Was it a basic service or interim service? If so (basically anything other
than a major/20,000 mile service), then there's a chance the fuel filter
wasn't replaced. What's the mileage on the car? Do you know when the fuel
filter was last replaced? Maybe might be worth getting it done.

Regarding slick-50 and such like - a lot of people I know wouldn't touch it
with a barge pole. There are websites dedicated to the technical ins and
outs of exactly how it can potentially completely ruin your engine, but in
short it's to do with the fact that the additives in stuff like Slick 50
which claim to prevent leaks are exactly the same additives that result in
clogged oil pipes etc. At the end of the day oil companies spend billions
in their research and getting their products exactly right, and any decent
additives worth putting in their oils will be in there already.

Peter

 

is it a 3 litre? my omega only averages that and if its an auto and the air
con compressor is on that will not help either

 

Was it a basic service or interim service? If so (basically anything
other

It was a 40K service but it had done 47K (not my fault, I've only recently
got the car!). Think I will try a new fuel filter though, it's not going to
cost alot.

Cheers, that's what I thought, best stick to decent oil instead then

Thanks for all the comments, this is one of the best/most helpful newsgroups
I've posted in

Chris

 

Was it a basic service or interim service? If so (basically anything
other

A fuel filter could well have been replaced as part of a 40k service (though
a lot of main dealers are quite useless and would probably forget) - check
the invoice for the service to see if it was replaced. If it has, don't
bother getting your hands dirty. How long are the journeys the car's used
for anyway? If they're all <1 mile then I'd say your economy is fairly
standard.

Helpful? All of my comments are largely guesswork

Peter