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Old 08-11-2020, 01:40 AM   #1 (permalink)
Engineering first
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Join Date: Mar 2009
Location: Huntsville, AL
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Last 3: 45.67 mpg (US)

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Tesla Model 3 battery degradation tuning


I wanted to share my experimental tuning of a 2019 Std Rng Plus Model 3 to compensate for battery degradation. Widely reported, the first year is ~5% followed by a 1% loss every year. My battery is about 3-4% (not an easy metric) so I wanted to start a tuning effort to compensate for the initial loss.

My first effort is to replace the OEM rims and tires with lower weight rims and lower rolling drag tires. My particular car has a single, rear drive motor and ~50 kWh battery, 2/3ds the size of the other models. This means I can 'lighten up' on the tire loads because it is ~600 lbs (273 kg) lighter. Furthermore, I drive in "chill" mode, about 75% of the maximum, "standard" mode.

Using Consumer Reports claims:
  • Bridgestone EP422 Plus - low rolling resistance series
  • 235/45R18 -> 225/55R18 - narrow tread and lighter weight
  • lighter weight rims
Compared to the OEM rims and tires, each saves ~5 lbs (2.8 kg) times four tires. Unfortunately, the front has an overhanding, king pin support that forced the first two tires to be on the rear only. Regardless, the high wear rating means these tires should last at least 2-3x longer than the OEM.

An on-going experiment, the front tires have a low wear rating and a recent screw event meant the local tire shop would not repair it. The "Stop and Go" kit using a mushroom shaped plug failed so I reverted to 'sticky string' which so far, is doing OK.

I have three candidate, front tires and am leaning to lowest rolling resistance tire with modest wear rating. Since the front wheels are not powered, they should have an 'easy life'. We typically saw ~2x difference between the powered versus unpowered tires in our past Prius.



Bob Wilson

2019 Std. Range Plus Model 3 - 134 MPG3 || 2014 BMW i3-REx - 117 MPGe, 39 MPG
JuiceBox 40 Pro (240 VAC, 40 A), KHONS portable (120-240 VAC, 12-32 A)
Retired engineer, Huntsville, AL (five times AutoPilot saved.)

Last edited by bwilson4web; 08-11-2020 at 05:02 PM..
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