Fuel Economy 1.8 Petrol

[Wolfie01]

Hi All

I recently purchased a 1.8 petrol LS 2003 with 70k on it.

It was serviced etc prior to me buying it after a few months I got a P0170 fuel trim bank 1 error, I was told by a local garage to replace the MAF, so I put in a Bosch MAF. Most of my driving is local and from £20's worth of fuel I am lucky to get 80 miles.

Is that about right or could it be one of the other sensors? A friend recommended putting Cataclean in, to improve the fuel economy.

In two mins whether to try this stuff, or whether I should get a proper diagnostics done from HI-Q as the P0170 code was read using one of the RAC readers from Argos.

[CLOMP]

so many things can cause a bad mpg, I dont know why but mine is very good on juce, if I drive my mates I get 5/7 mpg LESS so it aint all down to my driving style, but all local around stoke would get aprox 130 miles for 20 quid at to-days prices, on the 1.8 I have found that plugs (i use bosch super) make a difference as does fully synth oil and a clean air filter, mates car is a vvt on 60,000 mine is none vvt on 78,000, it makes no sense why my car is better on the juice, but all cars a different.

[mxt]

Hi All

It was serviced etc prior to me buying it .

We have had a few posts about "Service" and the vagueness of it.

Like you my car was "Serviced" before purchase - but it still had the same black oil in it as when I test drove it and the air filter was dirty. Changed Air filter and got around extra 5mpg Now changed oil so waiting to see what difference that will make - I followed Clomp recomendation for DEXOS2 (£22 from ebay / dealer - but different dealer have different price - 1 quoted £45)

[Bigtee]

We have had a few posts about "Service" and the vagueness of it.

Like you my car was "Serviced" before purchase - but it still had the same black oil in it as when I test drove it and the air filter was dirty. Changed Air filter and got around extra 5mpg Now changed oil so waiting to see what difference that will make - I followed Clomp recomendation for DEXOS2 (£22 from ebay / dealer - but different dealer have different price - 1 quoted £45)

Couldn't agree more.!!

Many have a service yes a oil service and the visual check.

So do check as above you may need some new filters and plugs.

[kdadidog]

sorry for butting in but what are the best plugs for a 1.8? mine has standard ngk ones and I only get maybe 90 miles from £20 fuel. Oh and i've got k&n panel filter and did the airbox mod along with a shorter intake that doesn't go across the radiator.

[Exclusive BV]

I am getting roughly 130 miles from 1/4 tank (20 litres) in my 1.8 vvti.

It's been around 6k since the last service and the oil is mingin!

I am getting the oil and filter done next week for £40 quid (Vx Fully Synth)

[Tony W]

This is my experience....

http://www.vectra-c.com/forum/showthread.php?t=127680

I think the only proper way is to Fill up the tank..do your journeys...
Fill-up again.. Note the Mileage Covered....then the amount of petrol to fill up again in litres/4.546 to convert to gallons.....

Then divide the mileage covered by the gallons needed to fill-up...

There you have the MPG for the period in question.....which in my opinion is more relevant than trying to Judge how much has been used from reading the fuel gauge or even using the on board computer if the car is fitted with one for actual fuel used.....

Lots. of threads/posts on fuel consumption on here....

Cheers

[luke.oldham]

mine a 1.8 16v LS 52 reg 80.000 miles i gave it a full service last week and im still only getting 17/20 miles to a gallon.its really ****ing me off.im sure i should be getting more than that. luke.

[Exclusive BV]

I am getting roughly 130 miles from 1/4 tank (20 litres) in my 1.8 vvti.

It's been around 6k since the last service and the oil is mingin!

I am getting the oil and filter done next week for £40 quid (Vx Fully Synth)

That should have been 15 and a bit litres

I use the above method mentioned by Tony somethimes (i dont have the trip computer) and i get around 32.5 mpg

[CLOMP]

sorry for butting in but what are the best plugs for a 1.8? mine has standard ngk ones and I only get maybe 90 miles from £20 fuel. Oh and i've got k&n panel filter and did the airbox mod along with a shorter intake that doesn't go across the radiator.

when I got my vec-c it had been serviced by VX,but only doing 32 mpg, Book stamped ect, any way took plugs out, and they were not good, did a full sercice but put in VX oe plugs,, all was well until aprox12,000 miles later, so took the plugs out just to have a lookie see,, although they looked a perfect colour,, all the electrodes were a different gap,(3 per plug) some were tiny almost closed up and some were massive, so I put bosch super twin spark in and mpg went back to norm,, after 10,000 miles decided to have a lookie see how the bosch plugs were doing,, they were perfect,, good colour and all gaps the same,, so its bosch plugs for me,, AND yes I do know that bosch make the oe plugs for a vec