Hi all as you know is have my new Astra 1.8 but starting to get worried about how much fuel its drinking! just thinking if a different air filter would increase or decrease the fuel economy?

Also looking to get some big wheels for it (i love wheels) just wondering if as its an auto that the different size wheels would mess anything up ie gear changing etc..

would this void my warranty?

apart from this I'm loving the car trying to keep it clean as possible!

If you upsize the wheels just lower the profile of the tyres accordingly, im sure someone more knowledgeable than me will tell you the ratio. Is it a petrol or diesel, check your tyre pressures, clean air filters etc i suppose.

Get a new clean OEM paper filter in it.

As for drinking fuel.... it's an auto, that is what they do.

Big wheels can mess your speedo up and cause the ride to be crashy, plus can do over acceleration due to an increase in unsprung mass. The dealer may decide to not honor the warrenty on some items due to this.

It's a 1.8l petrol auto; that's what they do. Just how bad is it?

If you upsize the wheels but fit lower profile tyres, you can keep the same rolling radius give or take about the depth of the usable tread. Someone's just posted a link to a size calculator over in "maintenance and performance". What CM says on the subject is all potentially true, but not in every case.

Just how bad is the fuel economy?

well... it does about 350 miles to 50 litres which is not good at all!

still compared to my 1.4 its as if the new car has a hole in the tank! never mind such is life

i wont be using the sport button any more using kickdown

i will let you know how many miles i get not using sport button to show off and not 'kicking down' much

I make that about 31.5 mpg which isn't that bad considering. Considering that I only got 33 from a 1.8 petrol Mondeo, but that involved driving at some, ah, quick speeds when overtaking.

I make that about 31.5 mpg which isn't that bad considering. Considering that I only got 33 from a 1.8 petrol Mondeo, but that involved driving at some, ah, quick speeds when overtaking.

ahh so its not as bad as i thought then? nice one !

just being paranoid i guess.. will have to hope petrol does not go up much more.. thanks

We have a 1.3 Yaris and its an auto for my Mum and that does 40mpg, so I am thinking that’s about right to be honest.

To get more mpg, check your tyre pressures, don’t fill the tank to the max mark, take any unnecessary things out of the boot, and avoid if possible journeys of less than 2 miles.

Look ahead at road conditions and avoid heavy braking.

32 mpg is better than a friend gets out of his manual 1.8 astra so its not that bad.

wow thats good then plus i know most will disagree but auto is more fun like playing a racing game all the time

also i checked my tyre pressures when i brought the car after it had an mot and service. in the book it tells me my tyre pressures should be 32 all round but when i checked my tyres were ALOT more

the front 2 were 42 and the back 2 at 38

i let quite abit out.. do you think the book is correct or are murketts just ****

I'd suspect Murkett's myself, presuming you checked pressures cold using a decent pencil gauge. If you checked pressures hot, that could be 10PSI, and similarly if you checked them cool, but using a garage airline or a gauge on an electric pump.

Oh and I don't like autos except for town driving. The only one I've driven that didn't jerk every single change and either change up too early or too late on full bore is my mum's Jazz, which is actually a CVT.

You MPG is about right really. I used to struggle to get 32mpg out of my Passat 1.8T on the otherside I used to be able to average 33mpg in my Volvo S80 T6 on a long run which was pretty good.

I'd suspect Murkett's myself, presuming you checked pressures cold using a decent pencil gauge. If you checked pressures hot, that could be 10PSI, and similarly if you checked them cool, but using a garage airline or a gauge on an electric pump.

Oh and I don't like autos except for town driving. The only one I've driven that didn't jerk every single change and either change up too early or too late on full bore is my mum's Jazz, which is actually a CVT.

i have a digital pressure gauge which seems to give pretty accurate results. i will check tomorrow when they are cold but how can you pump them up at the garage if they are warm? allow an extra 10psi cant be the best way?

We did try to tell you about the MPG :P - plus it's only a 4spd box, which won't help when you're at mway cruising speeds (if you do any of that kind of driving?)

Taking out the air filter and inspecting it won't do any harm, and yes, if it's dirty and clogged up, cleaning it out or fitting a new one should help matters.

Steve

i have a digital pressure gauge which seems to give pretty accurate results. i will check tomorrow when they are cold but how can you pump them up at the garage if they are warm? allow an extra 10psi cant be the best way?

I don't have a note of what it is to hand, but there's a British Standard for pressure gauges, which certifies their calibration accuracy. I just picked on a pen type because they're dead cheap and utterly bullet-proof!

Personally, I also posess a footpump (or if that doesn't appeal you can get portable electric pumps). Alternatively you could check and note the pressures cold, go to the garage and check again, giving you the pressure rise, and inflate soft tyres based on adding the cold underpressure to the present hot pressure.

Hi all as you know is have my new Astra 1.8 but starting to get worried about how much fuel its drinking! just thinking if a different air filter would increase or decrease the fuel economy?

Also looking to get some big wheels for it (i love wheels) just wondering if as its an auto that the different size wheels would mess anything up ie gear changing etc..

would this void my warranty?

apart from this I'm loving the car trying to keep it clean as possible!

the small block vx engines dont work very well with cone type filters if you were thinking along those routes. most loose power and use more fuel. stick with oem ones or a panle filter. as has been said you can up the size of wheels if you lower the tyre height. to play it safe what about getting some larger vx wheels from a sri or vxr astra? if they put them on other astras they wouldnt be out of place on yours

well... it does about 350 miles to 50 litres which is not good at all!

still compared to my 1.4 its as if the new car has a hole in the tank! never mind such is life

i wont be using the sport button any more using kickdown

i will let you know how many miles i get not using sport button to show off and not 'kicking down' much

thats not bad for an astra, my last astra did 350-390 per full tank of fuel and that was a 1.6 petrol.

i have been looking at the bigger sxi wheels and maybe vxr wheels but just thinking about insurance will it add money on the premium? when i put alloys on my fabia obviously it added £100 to the insurance because a std fabia has no alloys (well mine didnt anyway) so if my astra has alloys already will it still go up?

thats not bad for an astra, my last astra did 350-390 per full tank of fuel and that was a 1.6 petrol.

yeah, I didn't think that was bad either; It's noticably more than I tend to get in my (now ageing) 1.8 Focus

i found it didnt matter if i ragged the hell out of it or drove sensibly it drank the same amount.

yeah, I didn't think that was bad either; It's noticably more than I tend to get in my (now ageing) 1.8 Focus

The 1.8 Focus I had was woeful on fuel, would rarely better high 20s - in fact that was the prime reason I sold it and bought my first vRS

Steve

Ive checked my Tyre pressures cold then hot and inflated them according to the difference as my petrol is still going down rapidly.. just wondering, if your tires are OVER inflated does this reduce fuel economy or just screw the tires up?

also with an auto when rolling up to a set of traffic lights or such if you hit it into neutral and stay in neutral while the lights are red then back to drive to go, would this save petrol ???

Ta

That's the one positive for over-inflation; it reduces sidewall flexing, which will save a little fuel. However, since total mechanical drag with correctly inflated tyres uses about 20bhp at 50mph (cos I can remember the figures, at least for a manual box, there), is a linear relationship between power and speed once you're in top gear and engine, gearbox and driveshaft drag use about 18 of that, you'd see next to no benefit (if you halved tyre drag by overinflating you'd save about 1% fuel consumption), but you would significantly increase wear down the middles of the tyres, and potentially be looking at an instant driving ban (3 points for each incorrectly inflated tyre).

I don't think selecting neutral at lights would save fuel, but don't know that either way. I've just never bothered unless I thought I was going to be stopped long enough to be worth switching off.

New Question ************

What are the best head light bulbs for a mk5 astra i want some that are really bright because mine are so so dull at the moment driving in the dark is really hard..

also is there a way to make the lights shine higher up than the 3 preset settings from inside

thanks people