Ways to improve gas mileage / emissions?

[StudioWizard]

My 2005 2.5i is getting decent gas mileage, but I think I can get even better gas mileage possibly with better tires. But I was wondering if anyone has dialed in the best combination of tire roll/coast efficiency and handling.

Are there any other tweaks that can be made to the car to improve gas mileage other than driving it super conservatively?

Lastly, I know this car has a fairly high emissions rating (ie, it's a polluter)... Are there any tweaks to make it a cleaner, less polluting car?

[Chris_D]

I think you’re asking questions that many zed owners don’t particularly care about, unless they’re dailying their cars and even then it’s a maybe.
If you’re looking to save money on those ludicrous Commiefornia fuel prices then you already practically answered your own question -by driving it conservatively you will save a lot of fuel; coasting up to traffic lights as far back as you can, short-shifting, skipping gears, not blasting away from traffic lights, not reaching for the redline, or racing, driving with the hood up are all other habits you should be utilising. Tyres with a lower rolling resistance are going to give you a very marginal gain over those techniques I already mentioned.
Not driving it short distances for pointless journeys is not only going to save you money but also wear and tear on your car. Get a bike or hoof it!

[j3nks79]

Sounds like you’re in the wrong car.
Buy a Prius and sleep easy at night

[buzyg]

Seriously. Buying skinny hard tyres to put on a Z4.

[mmm-five]

You may spend more on 'fuel efficient' tires/tyres than you'd get from the saving those tires/tyres provide.

Just drive it, and enjoy it...and consider we were paying close to £1.80/$2.30 per litre ($8.50/US gallon) or not long ago...and currently about £1.40/$1.75 ($6.60/US gallon).

[enuff_zed]

M54 engine?
If not done already then get the vanos seals replaced. That will make the valve timing work properly again.
On wifey’s 2.5i auto we saw an improvement of between 1 and 2 miles per English gallon.

[StudioWizard]

I think you’re asking questions that many zed owners don’t particularly care about, unless they’re dailying their cars and even then it’s a maybe.
If you’re looking to save money on those ludicrous Commiefornia fuel prices then you already practically answered your own question -by driving it conservatively you will save a lot of fuel; coasting up to traffic lights as far back as you can, short-shifting, skipping gears, not blasting away from traffic lights, not reaching for the redline, or racing, driving with the hood up are all other habits you should be utilising. Tyres with a lower rolling resistance are going to give you a very marginal gain over those techniques I already mentioned.
Not driving it short distances for pointless journeys is not only going to save you money but also wear and tear on your car. Get a bike or hoof it!

I've seen some other posts on other forums talking about maximizing fuel efficiency.

[StudioWizard]

Sounds like you’re in the wrong car.
Buy a Prius and sleep easy at night

Not at all. I love this car. And I bought after renting from a buddy for several months, so it's not like I didn't know what I was getting into. Also, there's nothing wrong with trying to maximize every aspect of the car. I enjoy driving it like a sports car occasionally, but I also don't want the car to guzzle MORE gas than it should or pollute MORE than it should.

[StudioWizard]

M54 engine?
If not done already then get the vanos seals replaced. That will make the valve timing work properly again.
On wifey’s 2.5i auto we saw an improvement of between 1 and 2 miles per English gallon.

Good tip. I'll ask my mechanic about that.

[j3nks79]

Sounds like you’re in the wrong car.
Buy a Prius and sleep easy at night

Not at all. I love this car. And I bought after renting from a buddy for several months, so it's not like I didn't know what I was getting into. Also, there's nothing wrong with trying to maximize every aspect of the car. I enjoy driving it like a sports car occasionally, but I also don't want the car to guzzle MORE gas than it should or pollute MORE than it should.

Yeah I’m not in the same camp as I don’t believe in all this Global warming or Climate change. Or whatever else they are calling it at the moment.
It’s all just another way to tax us.

[Chris_D]

I've seen some other posts on other forums talking about maximizing fuel efficiency.

..and I can imagine they also probably talk about such hefty topics such as which are the most comfortable slippers, best smoking pipe, best incontinence pants, best toupe/denture glue, best way to sneak a crafty pee while out on the golfcourse, best places to frequent in order to catch a hot, frisky widower on a Friday night, etc.

[Mike6]

Make sure you change the air filter regularly, that often gets overlooked on servicing. I would
Also get a more free flowing air filter like K&N, change oil much more regularly than service recommendations. Also check brakes are not binding and buy a good petrol rather than supermarket rubbish. I also add reddex to my petrol periodically Which I know people think of as snake oil but it is supposed to aid mpg.

[StudioWizard]

Sounds like you’re in the wrong car.
Buy a Prius and sleep easy at night

Not at all. I love this car. And I bought after renting from a buddy for several months, so it's not like I didn't know what I was getting into. Also, there's nothing wrong with trying to maximize every aspect of the car. I enjoy driving it like a sports car occasionally, but I also don't want the car to guzzle MORE gas than it should or pollute MORE than it should.

Yeah I’m not in the same camp as I don’t believe in all this Global warming or Climate change. Or whatever else they are calling it at the moment.
It’s all just another way to tax us.

My OP has nothing to do with global warming or taxation. LOL I just want the car to run at its best. Whether or not global warming is a thing or whether or not it's caused by pollution doesn't matter to me for the sake of this post. C'mon, guys. Let's stay on topic here. haha

[StudioWizard]

I've seen some other posts on other forums talking about maximizing fuel efficiency.

..and I can imagine they also probably talk about such hefty topics such as which are the most comfortable slippers, best smoking pipe, best incontinence pants, best toupe/denture glue, best way to sneak a crafty pee while out on the golfcourse, best places to frequent in order to catch a hot, frisky widower on a Friday night, etc.

Wow, you're really taking my questions as a jumping off point for something else. That's OK. There are still some useful answers on here so far which I greatly appreciate.

[j3nks79]

Not at all. I love this car. And I bought after renting from a buddy for several months, so it's not like I didn't know what I was getting into. Also, there's nothing wrong with trying to maximize every aspect of the car. I enjoy driving it like a sports car occasionally, but I also don't want the car to guzzle MORE gas than it should or pollute MORE than it should.

Yeah I’m not in the same camp as I don’t believe in all this Global warming or Climate change. Or whatever else they are calling it at the moment.
It’s all just another way to tax us.

My OP has nothing to do with global warming or taxation. LOL I just want the car to run at its best. Whether or not global warming is a thing or whether or not it's caused by pollution doesn't matter to me for the sake of this post. C'mon, guys. Let's stay on topic here. haha

You mention emissions and pollution!?
Anyway this is all very boring. Hope you find a solution to your problem.