I doubt you'll notice any difference in economy or acceleration going down to a 225mm width. The aspect ratio would also need to be about 50 rather then the 25-35 you mention. A 225/25-18 is about 5" smaller than your current 245/45-18 so would look bizarre.

 

I think you'll gain most by going down in rim size. My G uses less fuel on the 17 inch winter tires than the 18 inch summer tires. Same width 225.

 

To notice any real difference you would need the skinniest, hardest compound (so not grippy) and lightest construction tyre you can find and run it at about 50 PSI…..not ideal I'm sure you will agree!!!

 

In urban traffic, the tyre size doesn't make a lot of difference in fuel consumption. What makes the car consume most is its weight in combination with the engine and drive train. You got a heavy car with a big engine that is optimized for long distance travels (diesel). But it is not good for urban short distance, stop and go, etc.

So, for better fuel consumption on long distance travels, you could choose a smaller rim size (16" or 17") with the right tyre size (as approved by Alfa and MOT). Smaller rims are lighter. You can inflate the tyres with 0,2-0,3 bars of additional pressure. Some (premium) manufacturers produce special "eco" tyres that are optimized for lower fuel consumption. But getting a set of rims with new, premium quality tyres will cost you more than you will save in fuel…

Best "objective" idea would be to get a vehicle that is better suited for your needs, like a smaller car with a small engine, an electrical vehicle, or a scooter or a bike.

Or just pay the bills and enjoy your Alfa

 

You cant fail an MOT for the wrong size tyres.....they don't even check what the stock size should be. As long as they are not different sizes on the same axle or dangerously wide or narrow for the rim width and you don't mix unidirectional and std tyres or tyre types (crossplies with radials for example) or excessively touching the body work (small area of contact are allowed) then it will pass....

 

The correct factory 18” size is 235/45/18, had them on my Brera for many a year [emoji106]


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Your only safe and legal option is to go to the 17'' wheels with the standard 225 50 17 which do have a slightly smaller rolling radius than the 18 and 19 standard sizes and then choose a tyre designed for low rolling resistance, there are quite a few eco tyres on the market.
Going to a lower profile, do they even make a 225 30 tyre? You will be outside of the manufacturer specs including load rating.

 

Your best bet is buying something like Michelin energy tyre, or a brand designed for fuel saving, but it really defeats the object of saving money having to buy new tyres, presuming that’s the reason for starting a thread?

I’d say remove as much weight as possible from the car that’s not needed.

Empty the boot, glovebox, etc...

Remove spare wheel and jack, carry tyre weld instead.

Change you driving technics

Scrap the tyre option. Michelin claim 20% less rolling resistance on 15/16 rims.
Just remove weight


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Surely the fuel consumption cant be that bad on a 2.4 d anyway can it?

 

25mpg 30mpg on a run, that's what I get. I don't hang about though.

 

I did some research on tyres and your best bet is to shop around and check the labels on each type, you will find some of the more budget type tyres have better fuel consumption, noise levels and grip than some of the more expensive type.
I opted for some Landsail tyres and found them to be way better than the P-Zeros I had fitted in many respects.

 

I think landsails would be a very good option to consider. They'll have no problem keeping your car on the tarmac while parked up in Tesco.

No sure I'd want to actually rely on them on the road!

 

Lol....tended to agree....until I read this! Not as horrendous as the name might suggest and a little better than a few big name tyres!

https://www.halfordsautocentres.com...s.com/advice/news/mar-2015-landsail-beats-michelin-surprise-result-in-tyre-test

 

Lol....tended to agree....until I read this!

https://www.halfordsautocentres.com...s.com/advice/news/mar-2015-landsail-beats-michelin-surprise-result-in-tyre-test

interesting for sure, but I would say more of a mark against the Michelin than in favour of the landsail. It's the Michelin which is out of place rather than the landsail and would like to see how many other tests bare out this result

Think I'll stick with my premium or mid-range tyres. (Yes I'm a tyre snob, but yes I do think it makes an important difference). Also, different tyres sizes between that test and the more usual UHP tyre tests in 18+inches and lower profile.

 

I tend to use well known but budget end tyres on my 159. I run Nexens at the moment and never had cause for complaint with them.....noise, wet and dry grip are more than enough for anything but ten tenths driving....and how often due you really drive like that on the road....its hardly a track day weapon lol! . Lets be honest is a heavyish car with only about 200 horse (in my case)…….how good a tyre does it need? Now when I was running 4 and 500 brake rear and 4 wheel drive cars.....well that was different!

 

I tend to use well known but budget end tyres on my 159. I run Nexens at the moment and never had cause for complaint with them.....noise wet and dry grip are more than enough for anything but ten tenths driving....and how often due you really drive like that on the road....its hardly a track day weapon lol! . Lets be honest is a heavyish car with only about 200 horse (in my case)…….how good a tyre does it need. Now when I was running 4 and 500 brake rear drive cars.....well that was different!

I would say Nexen are a midrange? same kind of group as Kumho, Uniroyal, Vredestein, Nokian, etc.

I agree but as you say, it's a heavy car and my tyres are easily the limiting factor in braking even in the dry and any improvement in tyres is going to make a difference in stopping distances. Laptime etc are definitely not that relevant for these cars, but it does translate to lateral grip under duress, i.e. if you need to swerve violently and brake for some reason either wet or dry that's where a UHP from michelin or conti or Pirelli etc will outclass a landsail or a nexen all day long.

 

Budget tyres maybe good in tests when they’re new against the premium brands, but as the thread wears down a few millimetres, I think you’ll find those test figures will widen much further.

Certain compound pellets are put into the tyre mix to improve the rubber compound. The big companies are always adding different pellets to improve the rubber compounds. Pirelli was always experimenting with the compound of the P series when they had that trouble in formula 1


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