Go Back   EcoModder Forum > EcoModding > General Efficiency Discussion
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 08-11-2020, 01:40 AM   #1 (permalink)
Engineering first
 
bwilson4web's Avatar
 
Join Date: Mar 2009
Location: Huntsville, AL
Posts: 791

14 i3-REx - '14 BMW i3-REx
Last 3: 45.67 mpg (US)

17 Prime Plus - '17 Toyota Prius Prime Plus
90 day: 58.25 mpg (US)
Thanks: 76
Thanked 196 Times in 126 Posts
Tesla Model 3 battery degradation tuning

Hi,

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.

Source: https://teslaownersonline.com/thread...-2#post-290660

Enjoy!

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..
  Reply With Quote
The Following User Says Thank You to bwilson4web For This Useful Post:
Daox (08-11-2020)
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 08-11-2020, 02:01 PM   #2 (permalink)
Master EcoModder
 
Join Date: Jan 2008
Location: Sacramento, CA
Posts: 395
Thanks: 31
Thanked 133 Times in 98 Posts
Quote:
Originally Posted by bwilson4web View Post
Hi,

This means I can 'lighten up' on the tire loads because it is ~600 lbs (1,320 kg) lighter. Furthermore, I drive in "chill" mode, about 75% of the maximum, "standard" mode...

Bob Wilson
Bob,
1320 kg=2900 pounds.
600 lbs=272 kg
I know it's just a typo.

JJ
  Reply With Quote
Old 08-11-2020, 02:48 PM   #3 (permalink)
Eco-ventor
 
jakobnev's Avatar
 
Join Date: Oct 2010
Location: sweden
Posts: 1,364

Princess - '92 Mazda MX-3 GS
House of Tudor
Team Mazda
90 day: 53.54 mpg (US)

Shirubāarō (*ω`*) - '05 Toyota Prius Executive
Team Toyota
90 day: 55.11 mpg (US)
Thanks: 59
Thanked 524 Times in 332 Posts
Send a message via MSN to jakobnev
How evenly does the battery wear? (Are some modules worse or better than others?)
__________________




2016: 128.75L for 1875.00km => 6.87L/100km (34.3MPG US)
2017: 209.14L for 4244.00km => 4.93L/100km (47.7MPG US)
  Reply With Quote
Old 08-11-2020, 05:01 PM   #4 (permalink)
Engineering first
 
bwilson4web's Avatar
 
Join Date: Mar 2009
Location: Huntsville, AL
Posts: 791

14 i3-REx - '14 BMW i3-REx
Last 3: 45.67 mpg (US)

17 Prime Plus - '17 Toyota Prius Prime Plus
90 day: 58.25 mpg (US)
Thanks: 76
Thanked 196 Times in 126 Posts
Quote:
Originally Posted by jjackstone View Post
Bob,
1320 kg=2900 pounds.
600 lbs=272 kg
I know it's just a typo.
THANKS! I know the ratio is 1-to-2.2 but more than once got it wrong.

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.)
  Reply With Quote
Old 08-11-2020, 05:06 PM   #5 (permalink)
Engineering first
 
bwilson4web's Avatar
 
Join Date: Mar 2009
Location: Huntsville, AL
Posts: 791

14 i3-REx - '14 BMW i3-REx
Last 3: 45.67 mpg (US)

17 Prime Plus - '17 Toyota Prius Prime Plus
90 day: 58.25 mpg (US)
Thanks: 76
Thanked 196 Times in 126 Posts
Quote:
Originally Posted by jakobnev View Post
How evenly does the battery wear? (Are some modules worse or better than others?)
I've not studied that but others, Sandy Munro and Jack Rickard, have reported very small differences. My interest is in temperature differences and they have been within a fraction of degrees C.

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; 08-14-2020 at 08:50 AM..
  Reply With Quote
Old 08-14-2020, 09:30 AM   #6 (permalink)
Engineering first
 
bwilson4web's Avatar
 
Join Date: Mar 2009
Location: Huntsville, AL
Posts: 791

14 i3-REx - '14 BMW i3-REx
Last 3: 45.67 mpg (US)

17 Prime Plus - '17 Toyota Prius Prime Plus
90 day: 58.25 mpg (US)
Thanks: 76
Thanked 196 Times in 126 Posts
Here are the first results:
  • Red line diamonds - a baseline recorded in March 2019 from our Std Rng Plus Model 3. It had the stock rims and tires with the aero covers.
  • Green line triangles - recorded August 11, 2020 with 18x8 Enkei trims and 225/55R18 Bridgestone ECOPIA EP422 Plus on the rear. The front tires are the Tire Rack recommended 235/45R18 Michelin Pilot Sport 4.
At lower speeds, the lower rolling resistance tires on the rear are working great. So now I need to look at aerodynamic tricks.

My first thought is rear wheel well pants. I can test it using heavy paper/cardboard and blue sticky tape. I'll only need to replicate the 63 mph benchmark. This approach doesn't add a rotating mass to the wheels.

There are rear spoilers sold but at $700, they are pricy and I'm seeing credible data showing a significant drag reduction. But I can hack-test with heavy paper/cardboard and blue sticky tape.

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.)
  Reply With Quote
Old 09-05-2020, 01:04 AM   #7 (permalink)
Engineering first
 
bwilson4web's Avatar
 
Join Date: Mar 2009
Location: Huntsville, AL
Posts: 791

14 i3-REx - '14 BMW i3-REx
Last 3: 45.67 mpg (US)

17 Prime Plus - '17 Toyota Prius Prime Plus
90 day: 58.25 mpg (US)
Thanks: 76
Thanked 196 Times in 126 Posts
Something I shared at Fred's TDI:

Just sharing some data points:
$37,990 - current price for Standard Range Plus Model 3 which includes basic AutoPilot
March 26, 2019 bought mine $41,000 with Autopilot and Blue paint
Got $18,300 trade-in on Prius Prime, net $22,700
Odometer 28,154 miles running version: 2020.36 updated two days ago
Local electricity $0.11/kWh
$2.70/100 miles ($0.027/mile) from house power
1/3 local electricity from free chargers while shopping
SuperChargers ~120-180 miles apart along Interstates
$3.50/100 miles using SuperCharger point-to-point
$3.00/100 miles staying overnight at a motel with free breakfast and charging
Other electricity
Can use RV and recreational area, NEMA 14-30 and 14-50 charging
Can use ordinary 110-120 VAC outlets (best to ask)
Typical cross country trips:
714 miles straight through to Detroit, ~14 hours, $25 charging
750 miles to Dallas, Coffeyville, and home
~90-95% of driving is using AutoPilot anywhere
Handles lane changes with 360 degree cameras
Unexpected medical issue handled by keeping car out of ditch and at speed
Full Self Driving (FSD), $6,000 last October
Stop sign, stop light, yield sign logic works with "green light" PING
Summon with dogs in car is amusing ... it looks like they are driving
Self-repairs
Banged into curb on passenger side, stripped part of rims yet tires held air
Replaced passenger side bearings using jack, jack stand, and ordinary hand tools
Battery degradation
Measured 3-4% in first year, miles: (240 - 234) / 240 and (240 -232) / 240
Subsequent years expecting 1% per year
Replaced OEM rims and tires compensates for initial degradation
Up to 45 mph, new rims and tires, 5 lbs lighter each, are better than OEM
Above 45 mph, I am working on aerodynamic hubcaps
Maintenance
Window washing fluid
Add air in Fall, monitor otherwise
One machine screw fixed by 'sticky string' plug
One sidewall puncture from road junk, road hazard warranty replaced
Driving
"Chill" mode so it won't 'speed frantic' in traffic
First across intersections at stop lights
Reach speed limit 200 yards ahead of everyone else
Cross country
1st leg with 100%, overnight charge to go as far as practical, ~210 mi, ~3 hours
next legs
Fast food for biology break, snacks and beverages
Drive to SuperCharger for 15-20 minutes to eat snacks and stretch
SUMMARY

Half the cost per mile of our former Prius Prime and fun to drive. The driver assistance of AutoPilot and FSD, makes long distance and even city driving safer, easier and relaxing.

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.)
  Reply With Quote
The Following User Says Thank You to bwilson4web For This Useful Post:
redpoint5 (09-05-2020)
Old 09-06-2020, 04:21 PM   #8 (permalink)
Master EcoModder
 
Join Date: Feb 2014
Location: Missoula, MT
Posts: 2,126

Dark Egg - '12 VW Touareg TDI Sport AWD
90 day: 25.81 mpg (US)
Thanks: 186
Thanked 895 Times in 615 Posts
Not to be picky but your Prius Prime would have made a 714 mile trip in 11 hours and cost the same $25 in "charging". Not sure how you get 1/2 the cost per mile. How long did those Model 3 tires last and how much were they to replace? That alone would buy years worth of Prius Prime gas, and a Prius is super easy on tires.
__________________

  Reply With Quote
The Following User Says Thank You to Hersbird For This Useful Post:
bwilson4web (09-06-2020)
Old 09-06-2020, 04:42 PM   #9 (permalink)
Engineering first
 
bwilson4web's Avatar
 
Join Date: Mar 2009
Location: Huntsville, AL
Posts: 791

14 i3-REx - '14 BMW i3-REx
Last 3: 45.67 mpg (US)

17 Prime Plus - '17 Toyota Prius Prime Plus
90 day: 58.25 mpg (US)
Thanks: 76
Thanked 196 Times in 126 Posts
Quote:
Originally Posted by Hersbird View Post
Not to be picky but your Prius Prime would have made a 714 mile trip in 11 hours and cost the same $25 in "charging". Not sure how you get 1/2 the cost per mile. How long did those Model 3 tires last and how much were they to replace? That alone would buy years worth of Prius Prime gas, and a Prius is super easy on tires.
“714 mile trip” is inaccurate. I drove that Prius Prime 1,200 miles from Rhode Island in just under 23 hours. It would have required a full tank at the start and a fuel stop on the way as my trip from Rhode Island did. But the real Prius Prime failure is the 25 mi EV range.

In Huntsville, the Prime became a ‘3 stop’ EV car while our BMW i3-REx was a ‘10 stop’ car. The BMW was used and the Prius Prime became driveway art. The majority of our miles are urban and that is where the Prime failed.

I was looking at a significant capital expense, $29,400, that was not returning value. So I traded it in, $18,300, for a Std Rng Plus a Model 3 that is cheaper both City and Highway. My capital expense must carry its weight.

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; 09-06-2020 at 04:50 PM..
  Reply With Quote
Old 09-06-2020, 05:57 PM   #10 (permalink)
Master EcoModder
 
Join Date: Feb 2014
Location: Missoula, MT
Posts: 2,126

Dark Egg - '12 VW Touareg TDI Sport AWD
90 day: 25.81 mpg (US)
Thanks: 186
Thanked 895 Times in 615 Posts
So you are counting the maximum possible depreciation cost by trading in after one year as a cost against the Prius? Are you only allowing the Prius to be used in EV mode? That seems like an unfair use, the whole purpose is to use that 40 mile range 80% or the time but then let the gas kick in when you need longer trips. Otherwise you are hauling around that big engine for no reason.

I just think in a fair comparison, normal usage, taking in all factors, no way the cost per mile on a model 3 is 1/2 a Prius Prime. Maybe pick something less efficient or more expensive car and you would get there, but a Prius Prime is not a high cost per mile car.

Your Tesla is a $47,000 car, you don't get to reduce it's cost by counting the Prius trade value as some kind of offset. If the Prius was a mistake for you, if anything that cost goes onto the Tesla's cost, not reducing the Tesla cost. If you look at your overall cost per mile over the last 3 years you are basically doing terrible. My $3500 3/4 ton Suburban does better getting 12 mpg.

__________________


Last edited by Hersbird; 09-06-2020 at 06:04 PM..
  Reply With Quote
The Following 2 Users Say Thank You to Hersbird For This Useful Post:
bwilson4web (09-06-2020), redpoint5 (09-06-2020)
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com