Probably less these days as it’s shown lower pressures and larger tires can improve performance.
Source?
All the studies I’ve read (and my experience) show that narrower tires and higher pressures improve economy. Less traction and less ride comfort are the tradeoffs, respectively.
GCN has a number of videos on this subject: https://youtu.be/jTZfrBVr5pQ?si=M5v6KP5ZZ9ZU5MXz
https://youtu.be/AK5KLvrzrb4?si=aMcYxYnWi9poZ8SA
And here is some technical data from SRAM: https://www.sram.com/globalassets/publicsites/cms-campaign-pages-not-story-pages/zipp/totalsystemeffeciency/pdf-downloads/tse-explained2.pdf
Basically new data includes vibration losses which get larger as pressure increases. There’s a sweet spot to balance between rolling resistance (which decreases with pressure) and vibration (which increases with pressure). So when you mention ride comfort as a trade off, it actually has a much larger effect than you might imagine.
Thanks for the videos and the PDF, but they are all bicycle related.
A car has a whole sophisticated subsystem dedicated for absorbing vibrations (the suspension), so I’m not sure the results can be applied there…
Yes fuel economy. Energy expended per distance traveled or power needed to maintain a given speed. Just the fuel in this case is burned by your own body.
At world class levels, a few watts here and there will make a big difference by the end of a race.
Aah, gotcha. I had thought that
Probably less these days
was in reference to this part at the end of the parent comment:
cars generally float around the 32 psi area
and I haven’t seen anything to contradict all the previous literature on under-inflated automobile tires being worse for fuel economy.