lightweight wheels model 3 performance 0-60 testing

[Sam1]

No way lightweight wheels are worth as much as 400lbs in the car. We're obeying physics here, right?

I don't even argue with people over it anymore. I was the first person to lose that much rotational mass and test with dragy and at the strip, only to come back with an absolutely irrelevant difference in times. Not a single person arguing that the reduction in weight makes a significant difference, has done it, or they wouldn't be arguing that view because they already found out that it does not work like a traditional car.

When I did my runs, the SoC was within 1% of each other, the weather conditions were within 5 degrees and sunny, and the battery pack temp was specifically heated up to over 105 degrees (seemed to be a sweet spot with the older battery packs). Battery temps have an enormous, undeniable, and factually provable major effect on performance so not sure why that isn't included when measuring any metric.

As for the MYP in that video that everyone loves to reference, what they don't mention is how the 20' MYP likes to clock in at about 3.4s 0-60 completely stock. Then, they also conveniently ignore the fact that the runs with the lighter wheels are done after multiple runs with the OEM wheels, which means the battery is hotter. I will take a hot battery at 74% SoC over a cool battery at 82% SoC any day of the week when looking at acceleration metrics.

 

[raptor5244]

I don't even argue with people over it anymore. I was the first person to lose that much rotational mass and test with dragy and at the strip, only to come back with an absolutely irrelevant difference in times. Not a single person arguing that the reduction in weight makes a significant difference, has done it, or they wouldn't be arguing that view because they already found out that it does not work like a traditional car.

When I did my runs, the SoC was within 1% of each other, the weather conditions were within 5 degrees and sunny, and the battery pack temp was specifically heated up to over 105 degrees (seemed to be a sweet spot with the older battery packs). Battery temps have an enormous, undeniable, and factually provable major effect on performance so not sure why that isn't included when measuring any metric.

As for the MYP in that video that everyone loves to reference, what they don't mention is how the 20' MYP likes to clock in at about 3.4s 0-60 completely stock. Then, they also conveniently ignore the fact that the runs with the lighter wheels are done after multiple runs with the OEM wheels, which means the battery is hotter. I will take a hot battery at 74% SoC over a cool battery at 82% SoC any day of the week when looking at acceleration metrics.

That is a pretty cool perk ov EVs if you can say regardless of whether you have one 110lb person or cram a family of cornhuskers weighing over 1000lbs combined the car still puts down the same times.

 

[gearchruncher]

That is a pretty cool perk ov EVs if you can say regardless of whether you have one 110lb person or cram a family of cornhuskers weighing over 1000lbs combined the car still puts down the same times.

Sort of, until you realize that it means the car was capable of a quicker acceleration when you didn't have all your friends in the back, and if you race the car, that's kind of what you care about...

 

[Sam1]

That is a pretty cool perk ov EVs if you can say regardless of whether you have one 110lb person or cram a family of cornhuskers weighing over 1000lbs combined the car still puts down the same times.

There's a reasonable limit to this issue. obviously if you add 25% of the vehicle's curb weight, it's going to have an effect. few hundred pounds makes zero difference on acceleration performance, but does make a huge difference in handling characteristics.

 

[raptor5244]

Sort of, until you realize that it means the car was capable of a quicker acceleration when you didn't have all your friends in the back, and if you race the car, that's kind of what you care about...

I am thinking 0-60mph sprints from Home Depot when I have a bunch of mulch in the trunk.

 

[Sam1]

It says you're from Florida, so you're going to need to up your game to impress us. Few bags of mulch in the back is not bragging rights from a state where people regularly punch alligators when they try to eat their children.

 

[dfwatt]

That is a pretty cool perk ov EVs if you can say regardless of whether you have one 110lb person or cram a family of cornhuskers weighing over 1000lbs combined the car still puts down the same times.

I guess you've also been converted to the view that there is no such thing as Newtonian mechanics and the fiction that power is infinitely adjusted by some magical process to make sure that the acceleration stays constant irrespective of what the car weighs? Perhaps you could tow an ocean liner and still accelerate 0 to 60 in two seconds?

 

[bedoig]

Thank you to both sides of this debate for convincing me to go ahead and buy a dragy. I guess my vtech from 1999 can finally rest in peace in a landfill (after I find it in some box, somewhere...)

 

[Sam1]

Thank you to both sides of this debate for convincing me to go ahead and buy a dragy. I guess my vtech from 1999 can finally rest in peace in a landfill (after I find it in some box, somewhere...)

View attachment 745091

Grab an obd reader and cable too for scanmytesla. Without knowing what the battery temps are, you're not going to be able to compare apples to apples if you want to start testing parts' benefits.

 

[bedoig]

Grab an obd reader and cable too for scanmytesla. Without knowing what the battery temps are, you're not going to be able to compare apples to apples if you want to start testing parts' benefits.

That part has been in place for years I just don't trust the speedo and CAN reading delays to give particularly accurate 0-60, etc results from ScanMyTesla.

And I do sometimes navigate to a supercharger with no intent of going there just to watch the temps and see my max kW discharge go up, lol.

Let science commence!

 

[bedoig]

I will say that my instinct would have been that @gearchruncher was right and the vehicle is always at it's amp limit. But I'm perfectly willing to concede that's wrong and the governing is more complex than I'd have expected since @Sam1 and others have tested while holding as much constant as they could. I'm not going on a buying spree for rotational mass reductions, but I can load a few hundred pounds of wife and children in the car for the communal scientific good I've actually just been eyeing the dragy for years.

Edit - sorry I didn't go back and re-read the thread. I may be misattributing things @dfwatt said to @gearchruncher. Whoever said it, my guess would have been the motors/inverters/etc are always operating at a defined peak and that weight reductions would make a difference like any other car, but those with actual data seem to say otherwise, so any interesting situation.

 

[raptor5244]

It says you're from Florida, so you're going to need to up your game to impress us. Few bags of mulch in the back is not bragging rights from a state where people regularly punch alligators when they try to eat their children.

Haha, this is true.

 

[raptor5244]

I guess you've also been converted to the view that there is no such thing as Newtonian mechanics and the fiction that power is infinitely adjusted by some magical process to make sure that the acceleration stays constant irrespective of what the car weighs? Perhaps you could tow an ocean liner and still accelerate 0 to 60 in two seconds?

I subscribe to fig newton theory.

Kidding aside, I have no idea but it is interesting how the Tesla M3 seems to be less impacted by increased weight than your typical ICE based vehicle. The car does feel like there may some software limiting at work but technically not sure if or what they are doing. From a performance perspective it almost feels like they have a target number they are after vs. dealing with pure physics alone. For example, do they try to target distance over time and dynamically command more power to achieve this target even if you add 400lbs? Conversely, if you remove weight, do they still just target a time and limit power? Is it simply that instant torque curve of EV drive units overcome the additional weight much better than ICE torque curve? No idea but I do enjoy the discussion as we all learn about EV driving dynamics.

 

[OUengineer]

Save your money, it makes zero difference. I removed iirc, 48 pounds between wheels and rotors, and my car was down to the 1/100th of a second identical on a 0-60. I was able to do the same times for a little lower SOCs on the lightweight setup than the OEM setup could, but it never actually went any faster. Driving feedback was awesome though

There are plenty others who have shaved a tenth of a second or more. Read through some of the acceleration related threads (may take awhile; they're long)

Anyone have any draggy testing for light weight wheels with the M3P? If so, would you mind posting the weight of the wheels and the draggy results? Trying to see if it is worth it to spend $2k on wheels.

As others have mentioned, you may be able to shave a tenth of a second, but it's not a guarantee. I went with flow formed wheels that looked good for a reasonable price and didnt worry too much about weight.

 

[Sam1]

There are plenty others who have shaved a tenth of a second or more. Read through some of the acceleration related threads (may take awhile; they're long)

People logging one or two runs better or worse with parts changes is irrelevant. Read my post debunking that internet story about how the light wheels magically supposedly sped up a MYP 0-60 by almost half a second. Same principle.

 

[Gauss Guzzler]

Guys, it would be absolutely asinine for Tesla to nerf the acceleration to 1G for marketing or dickish reasons. And it's virtually impossible to do that with an accelerometer which is picking up all sorts of road vibration in every direction.

But @gearchruncher is correct that the motor controller can and does very precisely measure and control rotational acceleration, non-inertially. Not only is this critically valuable for motor commutation and traction loss detection but it'd just be smart to limit motor acceleration to something on par with the maximum expected tire limits. Making this type of clever use of the incredibly precise control offered by an electric motor is what allows these cars to have such exceptional traction control.

Furthermore they are pretty well optimized to have power limits that are safe for the batteries, motors, inverters, and possibly other things (connectors, fuses, etc.). For example, when Tesla randomly pushes out a power boost update it's not because they're being cool and "unlocking" a little more for you, it's because they have done enough testing and data collection to be confident that the components can reliably handle more power than their initial estimate predicted.

So yeah, there's possibly some torque limiting to prevent wheelspin (which is effectively the same as G-limiting), then some current limiting to protect current sensitive components (current doesn't always correlate exactly with torque), then power limiting as some components are more sensitive to power than current, and then perhaps some time-based limiters which let you push some limits a little further for a short while. So it's certainly conceivable that some portions of the 0-60 run are hitting various software limits such that your tire/mass changes only affect part of the run and thus have less impact than expected.

And even if you aren't hitting any limits, you need to remove a heck of a lot of weight to make a measurable difference on a 3.1 second car, especially if you're measuring with something like Draggy which only gets a GPS position update once every .1 second.

 

[OUengineer]

People logging one or two runs better or worse with parts changes is irrelevant. Read my post debunking that internet story about how the light wheels magically supposedly sped up a MYP 0-60 by almost half a second. Same principle.

A half second is an obvious lie. But lightweight wheels are definitely faster. Whether it is measurable or negligible depends on the amount of weight savings. Any increase in power to weight ratio, no matter how small, will be faster.

Also, I wouldn't imagine there is significant difference between rotating and static weight with the amount of torque this car has. So it is not surprising that half the people that get lightweight wheels are unable to measure a definitive change in acceleration times.

 

[Sam1]

A half second is an obvious lie. But lightweight wheels are definitely faster. Whether it is measurable or negligible depends on the amount of weight savings. Any increase in power to weight ratio, no matter how small, will be faster.

Also, I wouldn't imagine there is significant difference between rotating and static weight with the amount of torque this car has. So it is not surprising that half the people that get lightweight wheels are unable to measure a definitive change in acceleration times.

Check out dragtimes slips, the top 40 model 3's are all within 0.09 seconds of each other on their 60 foot times. No matter the amount of mods. And I know one of those cars is completely gutted, without a single piece of trim even left on the inside.

You know why on a dragstrip that cars 400 pounds lighter and tons of unsprung weight removed, with extremely sticky tires still turn an identical 60 foot? Because the car is software limited. That's not one or two cars, that is a group of the fastest 40 different cars in various configurations, with traction removed as a variable, turning identical times.

And this is why I ignore one-off stories of why these parts made peoples' cars 1/10 faster on a 0-60 time, even ignoring the multiple hundreds of runs that I've personally done. Oh, and the fastest 0-60 I ever recorded was on the street, not the track, with the OEM 19" wheels and all season tires, not my sticky PS4S or light wheels, by 0.01 second.

But I'm not one to let pesky facts get in the way of someone's opinion, so feel free to get your car, and spends $8000 on parts to find out for yourself.

 

[gearchruncher]

Check out dragtimes slips, the top 40 model 3's are all within 0.09 seconds of each other on their 60 foot times. No matter the amount of mods. And I know one of those cars is completely gutted, without a single piece of trim even left on the inside.

You know why on a dragstrip that cars 400 pounds lighter and tons of unsprung weight removed, with extremely sticky tires still turn an identical 60 foot? Because the car is software limited.

Not sure that is a logical outcome of that data. If a vehicle is traction limited, lowering weight doesn't help, given less weight just leads to ratiometric less traction. A 0LB car has zero traction.

The Model 3 is clearly traction limited on street tires up to about 30 MPH. It behaves as if it becomes battery limited around about 40 MPH, as the power starts ramping down. So theoretically, 40-60 could be faster with less weight. However, we don't yet really know if that battery limit is real, or programmed, but 60' times tell you nothing about that speed range.

 

[Sam1]

Not sure that is a logical outcome of that data. If a vehicle is traction limited, lowering weight doesn't help, given less weight just leads to ratiometric less traction. A 0LB car has zero traction.

The Model 3 is clearly traction limited on street tires up to about 30 MPH. It behaves as if it becomes battery limited around about 40 MPH, as the power starts ramping down. So theoretically, 40-60 could be faster with less weight. However, we don't yet really know if that battery limit is real, or programmed, but 60' times tell you nothing about that speed range.

Sorry, should have been more clear. There are cars within a few thousands of each other on their 60 ft times, without regard to being completely stock, or completely modified and seeing a 10% total weight reduction on the vehicle. Those same vehicles are seeing 0.5 second variations on their 1/4 times, also without regard to modifications.

It's an example with a reasonably large sample size, to show that just because a couple of people are claiming that lighter wheels = faster times, doesn't mean it's fact.

As for the falsehood of the car being traction limited on the street, I have dragy recordings showing my car on all season tires, can turn an identical 60 foot time than those cars on a prepped surface with summer performance tires that have an extra inch width of tread.