<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>throwaway0a5e</author><text>Ballast for increased traction and tipping capacity with the positive side effect of lower COG.</text><parent_chain><item><author>xxpor</author><text>Hmm, why water filled? I can&amp;#x27;t think of any advantages, but can think of downsides such as a massive increase in unsprung weight.</text></item><item><author>arghwhat</author><text>A lot of heavy equipment drives around with water-filled tires, so it&amp;#x27;s already there. Definitely not what you meant though.</text></item><item><author>ddlsmurf</author><text>Complete layman here, every 6 months or so for the past decade I see an article claiming someone got air-less tires working. What are the chances this would be it ?</text></item><item><author>bkanber</author><text>Former automotive engineer chiming in. &amp;quot;Tweels&amp;quot; have been around a long time, but have always failed in terms of &amp;quot;NVH&amp;quot; (noise, vibration, harshness). Michelin is claiming that this generation of tweels are appropriate for passenger cars, which means that they &lt;i&gt;think&lt;/i&gt; they&amp;#x27;ve solved the NVH problem.&lt;p&gt;They seem to be marketing these alongside EVs, I wonder if they&amp;#x27;re only really intended for lighter, compact-style cars. (Edit: I&amp;#x27;m talking about EVs like the BMW i3, which &lt;i&gt;are&lt;/i&gt; on average about 1000 lbs lighter than the cars most Americans drive, ie, the CUV&amp;#x2F;SUV form factor.)</text></item></parent_chain></comment><story><title>Michelin Airless</title><url>https://www.michelin.com/en/innovation/vision-concept/airless/</url></story>
<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>jet_32951</author><text>The only springs on most tractors - ancient or modern - are between the seat and the frame to which it is affixed. IOW the vast majority of the tractor&amp;#x27;s total weight is unsprung.</text><parent_chain><item><author>xxpor</author><text>Hmm, why water filled? I can&amp;#x27;t think of any advantages, but can think of downsides such as a massive increase in unsprung weight.</text></item><item><author>arghwhat</author><text>A lot of heavy equipment drives around with water-filled tires, so it&amp;#x27;s already there. Definitely not what you meant though.</text></item><item><author>ddlsmurf</author><text>Complete layman here, every 6 months or so for the past decade I see an article claiming someone got air-less tires working. What are the chances this would be it ?</text></item><item><author>bkanber</author><text>Former automotive engineer chiming in. &amp;quot;Tweels&amp;quot; have been around a long time, but have always failed in terms of &amp;quot;NVH&amp;quot; (noise, vibration, harshness). Michelin is claiming that this generation of tweels are appropriate for passenger cars, which means that they &lt;i&gt;think&lt;/i&gt; they&amp;#x27;ve solved the NVH problem.&lt;p&gt;They seem to be marketing these alongside EVs, I wonder if they&amp;#x27;re only really intended for lighter, compact-style cars. (Edit: I&amp;#x27;m talking about EVs like the BMW i3, which &lt;i&gt;are&lt;/i&gt; on average about 1000 lbs lighter than the cars most Americans drive, ie, the CUV&amp;#x2F;SUV form factor.)</text></item></parent_chain></comment><story><title>Michelin Airless</title><url>https://www.michelin.com/en/innovation/vision-concept/airless/</url></story>