Is my car drinking to much?

PeterJames123

Hi All,

I have a Honda CRV Auto Petrol 54 Plate and I have been monitoring the petrol.

Yesterday I paid £20 for unleaded petrol at around 119p per litre and after 45 miles I need to refill. According to my calculations that is around 12mpg. All the websites and reviews that I have read for this say the car should be giving me at least 30mpg so I am unsure on what to do.

The tyres are full of air, the air filter has been changed, fresh oil so is there anything else I should be doing or should I sell this car on?

Thanks

tony6403

Presumably you are simply reading the fuel guage which may not be giving you an accurate indication.
Before deciding to get rid of the car , completely fill the tank and record the mileage. After , say , 150 miles fill it right up again and work out your mpg from the amount of fuel needed for that refill.
If it is 12mpg then you have problems ; maybe the gearbox stuck in first gear.

Richard53

As above, only one way to be sure of fuel consumption, and that is to measure actual fuel used against exact mileage. Fuel gauges and trip computers are often inaccurate, and the inaccuracy increases with very small measurements such as £20 of fuel and 45 miles.


I wouldn't expect anything worth basing a decision on with less than 500 miles of measured consumption. For example, I log every fill of fuel and my mpg can apparently vary by 2-3 mpg from tank to tank with identical usage. I put this down to slight variations in how full I get the tank each time - even half a litre here and there makes a big difference to the apparent figures. However, over 10k miles I can tell you the consumption to two decimal places.


I'm not proud of that, by the way. It's just a habit now.

facade

You may find that the lambda sensor at the exhaust manifold is failing.
This often results in increased fuel consumption, (and an MOT fail on emissions) but does not cause the "check engine" light to come on until it fails completely.

Could be worth a punt at a new one, as you will get the cost back in a few miles if it takes the consumption from 12 back to 20-22 MPG.

worried_jim

Start using -

http://www.fuelly.com/

mcpitman

Richard53 wrote: »

As above, only one way to be sure of fuel consumption, and that is to measure actual fuel used against exact mileage. Fuel gauges and trip computers are often inaccurate, and the inaccuracy increases with very small measurements such as £20 of fuel and 45 miles.


I wouldn't expect anything worth basing a decision on with less than 500 miles of measured consumption. For example, I log every fill of fuel and my mpg can apparently vary by 2-3 mpg from tank to tank with identical usage. I put this down to slight variations in how full I get the tank each time - even half a litre here and there makes a big difference to the apparent figures. However, over 10k miles I can tell you the consumption to two decimal places.


I'm not proud of that, by the way. It's just a habit now.

I do this too,

Advantage being if mpg drops off a cliff, yiou know there is an issue somewhere.

Dependant on your driving style and tyre pressures the returned numbers can vary quite alot.

Hintza

Richard53 wrote: »

I wouldn't expect anything worth basing a decision on with less than 500 miles of measured consumption.

That is fine for accurate mpg figures. But if as is possibly the case here the op is getting a quarter/third of what they should be a shorter test would probably suffice.

tykesi

What sort of driving was the 45 miles?

AdrianC

As others have said, if your "monitoring" involves sticking a splosh in then worrying when the gauge doesn't move much, that's next to useless.

Brim the tank (ignore that quantity), zero the tripmeter, brim the tank and use that second fill to calculate. Even better, average it over a few fills - THEN we'll talk. And, no, putting an extra 30kg of fuel into a 1500kg car will NOT make it "less economical".

But if you're just doing short trips with a cold engine, you will get markedly poorer economy at this time of year.

forgotmyname

I was doing the same many years ago when i had a classis mini, I seemed to be forever in the fuel station.

I only did short journeys at the time so not many miles at all. I thought this is silly so filled a can and decided to run the fuel down to empty and then check properly.
2 weeks later i still had not run out despite the gauge saying it was empty all that time.

Dont recommend that these days with the fuel filters being a PITA to change.

Your gauge wont be linear, It may move faster in some parts than others. The red line could be anywhere between 1 and 3 gallons depending on the gradiant and camber of the road your parked on.

Its not a fuel efficient car anyway. Sub 30mpg will be normal for town work.

James_B.

That's more than my car manages on £20 of petrol...

Anyway, as others have said, you need to work out the actual MPG with well-defined amounts going n and being used. The best way to do this is to fill the tank, do a decent number of miles, and then re-fill, and see how much you used for that distance.