In the Netherlands they use driving axle load systems usually in the right most lanes on the highway that feature trucks. There is also a service that automatically calculates the tire pressure and sends a message to the company if the tires are deflated when driving over these weigh points.
Weighing a Car with Tire Pressures
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Re: Weighing a Car with Tire Pressures
#82> The first thing I wanted to do with my Saab 96 was to establish a baseline weight. The cheapest scales used for racing are over $700, You can do this for (almost) free if you go to the local dump. They usually charge you based on weight of what you dump by weighing your car on the way in and on the way out. Just ask them what the reading is on the way out. If you bring a couple of pounds of garbage, it will cost a…
Both (in and out) numbers are usually printed on the receipt, as the charge is per weight dumped (with some minimal fees; for our waste management station that includes 320 pounds).
Re: Weighing a Car with Tire Pressures
#83> The first thing I wanted to do with my Saab 96 was to establish a baseline weight. The cheapest scales used for racing are over $700, You can do this for (almost) free if you go to the local dump. They usually charge you based on weight of what you dump by weighing your car on the way in and on the way out. Just ask them what the reading is on the way out. If you bring a couple of pounds of garbage, it will cost a…
In Santa Clara near the airport there was (and probably still is) a paper and cardboard recycler. The scale is off a public street near some train tracks. At some point in college we noticed that the scale stayed on at night and the weight was clearly visible in the kiosk across the street. So me and my car buddies used to weigh our cars there for free at night!
Re: Weighing a Car with Tire Pressures
#84By the way, a car with electric propulsion and regenerative braking should be able to "know" its weight quite precisely (from the amount energy that is needed to accelerate or the amount of energy that is returned when regen-braking).
Re: Weighing a Car with Tire Pressures
#85By the way, a car with electric propulsion and regenerative braking should be able to "know" its weight quite precisely (from the amount energy that is needed to accelerate or the amount of energy that is returned when regen-braking).
After you've subtracted the effect of thousands of hard to measure variables like the slope, the tyre rolling resistance, the resistance in the wiring, the magnetic flux saturation in the motor, the accuracy of the current sensors, etc, etc, etc...
Re: Weighing a Car with Tire Pressures
#86Upvoted for the Saab
Such a lovely vehicle!
Re: Weighing a Car with Tire Pressures
#87By the way, a car with electric propulsion and regenerative braking should be able to "know" its weight quite precisely (from the amount energy that is needed to accelerate or the amount of energy that is returned when regen-braking).
After you've subtracted the effect of thousands of hard to measure variables like the slope, the tyre rolling resistance, the resistance in the wiring, the magnetic flux saturation in the motor, the accuracy of the current sensors, etc, etc, etc...
Not thousands but a few and most of them are measured anyway, like slope with a gyro or battery drain.
No need to over complicate it just measure the amount of regen the more you get the more the car weighs.
Re: Weighing a Car with Tire Pressures
#88https://en.wikipedia.org/wiki/Saab_96 says “873–950 kg (1,925–2,094 lb)”. Middle of that range is 911½ kg (2,009½ lb).
Reading the comments here, that probably is more accurate than this hack. It isn’t as educational or entertaining, though.
Re: Weighing a Car with Tire Pressures
#89Back when Microsoft was doing those obscure job interview questsions like "how much does a 747 weigh", this was my solution, measure the deflection of the tires and the PSI to calculate weight. Apparently the answers they were looking for were more along the lines of "put the plane on an aircraft carrier in a lake and measure the water displacement"
Re: Weighing a Car with Tire Pressures
#90> I have a decent pressure gauge that I got for $25, so I feel I can be reasonably accurate. Such a false sense of confidence for a product[1] whose actual performance specs aren't properly published. And it isn't just Longacre playing this game. If you're in the recreational motorsports scene, you've probably noticed what I'm referring to. If you're an engineer in the same, it probably has driven you nuts. I'm not e…
Any recommendations for decently precise tire gauges ?