General what sort of mpg should you expect in a sei?

[Benjammo]

hi all well I've got my seicento back on the road after about 2 years, we had to get a "proper" family car so got a 2.4 turbo diesel volvo V70 D5.
as you'd expect theres a few niggles with the seicento but nothing that time and money carn't fix but I cant remember the MPG being so bad, I've half filled the tank and it lasts me 4 days to and from work, thats about 120-130 miles most of the time I'm sat on the motorway in 6th, 3,400 rpm ish doing 70. I've plugged my obd reader in and it says I'm getting 19mpg average and was getting 15-17mpg instantaneous sat on the motorway. cars been serviced a few weeks ago but havent changed the cone filter in a while, and the engine light is on, but thats just because the fan's buggered and doesn't switch on so I doubt that would cause bad mpg.
Is there anything else that you can think off that would cause bad mpg or is 12-130 miles on half a tank normal?

thanks

 

[fingers99]

That's dreadful. Thermostat stuck open? I used to do Liverpool to London and back nearly as fat as Birmingham on a full tank -- and I wasn't exactly hanging about. Also check for dragging brakes.

 

[Benjammo]

at the weekend I'll be jacking her up and putting a set of 14" wheels on so I will check the brakes, none of them feel hot after a drive but always worth checking. as for the thermostat, I hadn't thought of that, I'll have to check it out at the weekend too.

 

[gatsovictim]

Hi

I can get 47mpg on a motorway run doing about 60-70mph.

 

[Huwbishop]

Stick some injector cleaner through it. If it has been standing various bits can get a film of varnish on them. Running fresh fuel will clear it eventually, but a spot of cleaner will speed the process.

Also if you do mainly motorway driving, up the tyre pressures 5psi or so.

Saves a bit.

P.S. Cinq 1242 8v in mid wales, on twisty roads at 6am with no traffic. Still averaged 44mpg, and I was flying.

 

[Ralf S.]

The most likely cause is a dubious lamda sensor.

If it was idle all this time it could have corroded and is now FUBARd. Give the car a few miles to see if it burns off any corrosion and comes back... but at the price and seeing the beast is right there in front of the engine, I'd just be inclined to change it.

Ralf S.

 

[blu73]

i've had cars sit for longer than 2 years and never had trouble with lambda sensors. Seems wierd to me how quickly people jump at lambda sensors whenever anything is wrong.. I've had so many cento's now its silly and to date never had a lambda fail.

to benjammo, You been around for long enough to know your engine bay so assuming you had a poke about and checked pipes etc already. Whack some high octane fuel in it and give it a thrash, see if it improves then go from there is my opinion.

 

[GrumpyOldMan]

I would probably do as someone has suggested and spray clean the injectors a couple of times. It's a good thing to do on a regular basis anyway. Also put a bottle of Redex in your tank and then give it a good burn out.

I have an 899 Sei and on a good run get about 58 MPG.

By the way, what Sei do you have to have a 6th gear?

Ian.

 

[blu73]

some high octane fuel every once in a while is fine to clean out the injectors really, that and a bit of a thrash about

@ Grumpy: It'll be a 6-speed off a punto or other FIRE engined car with a 6 speed box. They fit straight on but you have to but steering lock reducers on to prevent the wheel from hitting the gearbox on full lock.

 

[Andy2011]

I get around 120 miles to half a tank, and 220 at a push till when the light comes on. But then again this is all short journeys or up 30mins if that. No motorway driving at all....

 

[blu73]

do remember the top half of the tank it alot bigger than the bottom half..