Widening Tires

I will soon replace my tires and I'm investigating. I would like to increase the width to improve the handling of my heavy 124, while keeping the wheel´s diameter the same (for transmission and speedometer precision). As you may know, this is only possible by lowering the tire's section height (currently 195/65 R15). WIth a lower section height the tire's deformation is less, and so it has lower capacity to absorb energy, therefore the ride should be rougher. If it is so, does tire manufacturers do something to compensate this loss, like improving the quality of the tire´s materials/rubbers? Is it advisable to lower the tire´s section height? Thanks

Reply to
MMansilla
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YOu don't get something for nothing. My 126 came with 195/65-14 and I switched to 205/50-15 and then 235/55-16. The ride is harsher but bloody hell does it corner better. Much more of a difference than gionf frm 14 to 15. The ride IS harsher. Straigh line stabiility IS affected as is wet performance. Like I care. It's not terrible and sometimes not really noticable. I wouldn't hesitate to do it again.

Reply to
Richard Sexton

Going up to 16" is good... I got 16 on my car now... the size you need at 16 is 205/55R16. I like the comfort and steering characteristic...

Going 17 is harsher but wider. I'd stick with 16 for price, comfort and performance wise.

Reply to
Tiger

What is so specially heavy about the W124?

DAS

For direct contact replace nospam with schmetterling

Reply to
Dori A Schmetterling

No, the tire mfg r's don't compensate for the harsher ride, in fact there's a further downside - they use softer rubber (for these "performance" tires to adhere to the road for improved handling) but that softer rubber wears out faster than the rubber used in higher aspect ratio tires. Just look at the relative wear index of what you have vs. the wider ones that you want. Then there's the curb issue - my old car has 70 tires and its alloys never have curb scrapes but the newer one has occasional curb - alloy scrapes because its tires are 55s!

The new S class M-B sales literature includes a disclaimer footnote about the 18 inch and 19 inch wheels and their corresponding low aspect ratio tires - something like a harsher ride and higher wear are to be expected. What a sales point!

Don't do it.

Reply to
T.G. Lambach

225/55R16 is actually closer to the original diameter; you're using one size smaller. That's ok, I'm using 235/55R16 - one size larger. Both work.

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Reply to
Richard Sexton

No... I know this topic very well...

205/55R16 215/55R16 215/50R16 225/50R16

These are all acceptable sizes.

Reply to
Tiger

Size Sidewall Radius Diameter Circumference Revs/mi Revs/km Diff 205/70-14 5.65/143mm 12.65/321mm 25.30/642mm 79.48/2018mm 797 495 205/55-16 4.44/112mm 12.44/315mm 24.88/631mm 78.16/1985mm 810 503 -1.69% 215/55-16 4.66/118mm 12.66/321mm 25.31/642mm 79.52/2019mm 796 495 0.05% 215/50-16 4.23/107mm 12.23/310mm 24.46/621mm 76.86/1952mm 824 512 -3.41% 225/50-16 4.43/112mm 12.43/315mm 24.86/631mm 78.09/1983mm 811 504 -1.77%

Should be within 2%, 215/55-15 is a tad small.

Reply to
Richard Sexton

Ahh... I thought you were talking about my car... the W124... which originally came with 195/65R15.

Yeah, when I had the W126, I ran the 225/50R16.

Reply to
Tiger

Thanks to all. I'm trying to make a good decision, four low profile tires and four (MB) rims aren´t cheap. From your posts and more searching I got this:

Wider and low profile tires means:

- Improved lateral stability, better handling.

- Better traction when accelarating and better braking power.

- Harsher riding due to less tire deformation. Can be compensated with better springs.

- Better fuel economy: less deformation means less tire heat. But this can be emulated by overinflating a bit a higher profile tire.

- More wearing, caused by softer rubber compounds.

- Less warning when you are about to lose control in curves.

Considering all this, and my driving style and conditions, I think is good to go wider, but not too much.

Reply to
MMansilla

It's not really heavy in absolute terms, but these 195 mm tires makes it feel heavy when cornering and in curves, IMO.

Reply to
MMansilla

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