Very bad mpg

Lorax

Hi guys, I drive an opel astra mk3 1.4 petrol and was just wondering could anyone tell me why I get such bad mpg compared to other drivers I know. When I get €10 petrol (which is about 9.4 litres in my local garage) I only get about 65 miles (or 80 miles when driving on motorway/national roads). My dad gets over 100 in his ford focus for the same amount of petrol. My exhaust is a bit dodgy (backbox needs replaced) would this affect it? I rarely ever over-rev the car like, so its not the way I drive. Any suggestions? thanks

Lorax

*Bump*

Yakuza

A bump after 10 minutes? Sorry, the team dedicated to answering your question was on its tea break

Old / dirty spark plugs perhaps? Buy one of those NCT kits (engine cleaner) and add it to an almost full tank of petrol).

Do you let the petrol go low often? Maybe some gunk got stuck in the fuel line or something. I generally fill my car, and fill again it as soon as the reserve light goes on.

johnnyrotten

Fuel economy comes down to a lot of things.
Driver's heavy foot
Correct use of gears and breaks
Correct tyre pressures
Open window(s)
Air con
BAd service record
Type of driving
Heavy traffic

The list goes on and on..........................

Anan1

The state of your exhaust can affect fuel consumption, as your engine has been designed to run with the back pressure supplied by a factory standard exhaust with no leaks. That said, a dodgy back box is less likely to affect running than a leak closer to the engine.

peasant

and if you only ever put 10 litres into your tank, condensation is another problem.

Moisture in the air (which is basically all that your tank contains:D ) will condensate on the tank surface and trickle down into the petrol, mixing with it and affect performance.

bazz26

When was the last time the car was serviced? What was done as part of that service? Also how heavy are you on the accelerator? A heavy right foot will contribute to poor fuel economy.

Check your air filter, it may need to be replaced. I found replacing the air filter in my car recently improved my fuel economy.

Lorax

Thanks for all the replies d00dz.

The last time the car was serviced was February 2006.

It needs new spark plugs/leads I'm pretty sure of that. Would that be the a large factor?

I am not heavy on the accelerator at all, and change gears correctly.

I did my tyres about 2 months ago to the correct pressures, and the threads on them are fine almost like new tyres.

I replaced the air filter about 3 weeks ago but it didn't change the fuel consumption.

Suppose the car needs a service but I'm getting rid of it in about 3-4 months so dunno would it be worth my while.

Wishbone Ash

Get the exhaust repaired and get it serviced.

(Why do you only get €10 per fill? It's much better, and less time consuming to fill the tank and drive until nearly empty. I generally get €70/80 a time and get about 450 miles in a 3 litre diesel.)

528i

If you're having problems with fuel consumption you should put €20,000 to that astra and buy a passat Tdi to rectify the situation.

C_Breeze

ehhhhh ... whats wrong with that ?????



that basically equates to around a consumption of 8l/100km combined. seems fine to me.


IS your dads focus diesel perhaps???!!!!!!!

AMurphy

Lorax wrote:

Hi guys, I drive an opel astra mk3 1.4 petrol and was just wondering could anyone tell me why I get such bad mpg compared to other drivers I know. When I get €10 petrol (which is about 9.4 litres in my local garage) I only get about 65 miles (or 80 miles when driving on motorway/national roads). My dad gets over 100 in his ford focus for the same amount of petrol. My exhaust is a bit dodgy (backbox needs replaced) would this affect it? I rarely ever over-rev the car like, so its not the way I drive. Any suggestions? thanks

Coudl be anythign and everything mentioned previously, including someone stealing your gas or a leak.

Waht year is this vehicle, does it have modern EFI/EGR, O2 sensor, Distributorless ingnition, etc or throttle body, no O2 or EGR, or Carb.

How many miles on it.

fletch

C_Breeze wrote:

ehhhhh ... whats wrong with that ?????



that basically equates to around a consumption of 8l/100km combined. seems fine to me.


IS your dads focus diesel perhaps???!!!!!!!

Yeh circa 30mpg is not too bad around town for a 1.4 petrol

zuutroy

your numbers add up to 30+ mpg around town and 40 on the motorway. Thats really not too bad. Follow a few of the suggesions on here and it might pick up a bit. I would add to check your thermostat aswell. If its stuck open, you'll have degraded mpg.

ninty9er

Lorax wrote:

I did my tyres about 2 months ago to the correct pressures, and the threads on them are fine almost like new tyres.

You haven't checked your tyres in 2 months:eek: :eek: