If you’re an owner of a BMW X3 M40i, upgrading to the proper X3 M is probably hugely attractive. However, it’s also hugely expensive. And, also, it might not be worth it, considering the harsher ride quality and worse fuel economy of the X3 M-proper. Maybe, instead, it’s worth just upgrading your X3 M40i with some new shoes.
Motor Trend recently gave their BMW X3 M40i long-term test car a wheel and tire upgrade to see if it made any difference in terms of performance and fun. Turns out, the upgrade made a huge difference.
Rather than the stock wheels, MT’s X3 M40i now has very lightweight OZ Hyper GT HLT wheels. Those new wheels are wrapped with Michelin Pilot Sport 4S tires, which are big upgrades over the stock Bridgetstones it was wearing. So does just a simple wheel/tire upgrade really make that much of a difference?
Apparently, yes. According to MT, the new setup dropped the car’s overall curb weight 34 pounds. That might not sound like a lot but that’s unsprung rotational mass that’s been reduced. So it actually makes the car feel lighter on its feet, while also improving ride quality. More that that, the new setup reduced braking distance from 60-0 mph by nine feet. That’s a huge difference. It also improved the BMW X3 M40i’s figure-eight time by almost a second, dropping it to 25-seconds flat. That makes the X3 M40i faster than the previous X6 M on MT’s figure-eight test.
Even more impressive, the stickier shoes and lighter weight helped improve the BMW X3 M40i’s 0-60 mph time by almost half of a second, dropping it to 4.4 seconds. That’s seriously quick and only about another half a second behind the proper X3 M. All while riding better and being significantly cheaper. I really love the BMW X3 M a lot but the X3 M40i with some upgrades might be the way to go.
[Source: Motor Trend]
Exactly why I generally prefer the Mxx class to the xM class of cars for real world driving. When one is cruising on the Interstate on a couple hundred mile trip between cities, an extra 25% mpg means more than an extra .5 seconds in passing another vehicle. Most of the M cars performance is not legally available on the street. Track, yes; street, not so much.
Why I particularly appreciate the M340i compared to the twice as expensive M5C. M5C is a plusher beast, especially above 80 mph, but it is a way thirstier one also. Now that M340i and M340ix have the M E-LSD, there is little compelling reason to go full on M3 for the street unless one just wants to. Personally, I would buy a M340i Competition if it had the M3 equipage with the totally adequate same B58 engine.
Car and Driver reported 42 mpg from their 330i. On our nasty streets, stock is the way to go, performance wear increases harshness (plus couldn’t get V8 M3 up a wet parking ramp or M550i out of a snowy lot on sport rubbers, friend put her awd. SUV in a ditch for the same reason).
It depends, efficiency means nothing when you drop $100k+ on a car. My X5 50i gets 14-16mpg and I don’t care. My X3 M40i averaged 18-21mpg usually which isn’t bad either. If you can afford to spend the money, you can afford the Fuel
Specific to tires only, there is a huge positive difference in ride, noise and handling by replacing OEM run flats with standard performance tires (I replaced with Michelin Pilot Sport A/S 3+).
Meanwhile my X3 M40i on All Season P Zeros could do
0-60 in 4.4s all day on a non-prepped surface
Yes.On m y 335i M Performance, going with 19″ Ray’s (10,000 ton press, one in Japan, manufacturer of BBS, Vorsteriner 18″ and higher, but as Ray’s, Japan, 30% of a BBS set) and MPS4S, I dropped 12 lbs front and 16 lbs rear, easily 28-30lbs less rotational mass. A transformative, indeed it felt as if the car was some 300 lbs lighter.
Then I added front 3D CCBs, so from 12.75 to 5 kgs, that is14 lbs less per disc, and it changed the car further..