Last updated 27-Dec-2021
This has become much less of an issue since the MCU2 and the Model 3 and Y launch. As such the guidance below is primarily aimed at buyers of older Model S and Model X cars built before 2019
There are two main technology families in Teslas that determine the features the car has, these are the Autopilot hardware and the Media Control unit (MCU).
Autopilot hardware has been through a number of generation, starting with no autopilot hardware and only limited passive sasfety technology, then the Mobileye system used in AP1, then 3 iterations of the Tesla hardware, commonly referred to as AP or HW2, HW2.5 and HW3, the last of which Tesla now term "full self driving computer". Even this last generation has two flavours, with and without the radar. Further, there has been talk of HW4 being in development.
The other familty of technology is the Media Control Unit or MCU. The original MCU1 was was installed until about 2018 where the MS and MX were upgraded to the MCU2 hardware which can also be retro fit. The Model 3 aqnd Model Y had a similar powered processor but the screen changed to landscape. While these appear to be similar, from V11 of the Tesla software the capabilities start to depart. The 2021 Model S and Model Y have a later generation of hardware again, we shall refer to as MCU3, and adopt the landscape format. There is also som evidence that Tesla is testing this latest hardware on the Model 3 and Model Y platform and may arrive in production cars in 2022.
Cars with FSD and older hardware are being upgraded to the lastest hardware if they haven't already had the upgrade. the hardware is also usually upgraded if owners buy the MCU upgrade (assuming they have HW2 or HW2.5). There is no upgrade path for AP1 and before.
To determine which features a car may have, see our guide to determine which version of autopilot is installed. It's worth noting that just because a car has full self driving hardware, it does not mean the car has the feature activated.
While Tesla have been keen to suggest that all cars built since their version of Autopilot came out in late 2016, now known as HW2, would support autopilot and they would offer free upgrades to anyone should they need it, Tesla have started to release features that do not work on all hardware versions, much to the annoyance of some owners although its primarily HW2 owners who are missing out, a double blow for those that bought their car new as they had to wait for nearly a year for any Autopilot features to be delivered.
While Tesla have called HW3 (introduced in mid 2019) the 'FSD hardware', and it is said to have twice the computing power of HW2.5 (which was introduced in 2018), the autopilot features are the same across all versions. What we suspect is happening is the software at times runs out of processing capacity and a situation may not be handled as well under the earlier versions compared to HW3. Tesla are said to still be optimising the code for HW2.5 and we can expect a jump in performance if not features when this happens. The problem Tesla have is maintaining backward comparability as even HW2 were sold as having everything needed for Full Self Driving. While upgrades are taking place for cars who have the FSD option, we suspect the real challenge will be in the performance of regular Autopilot features on cars with lower levels of AP hardware. This seems to be illustrated with HW3 cars being able to see and report cones and not the earlier versions and mixed reactions to cars detecting speed limits depending on AP hardware. Some owners claim AP2.5 cars have seen speed limits, others say not.
To determine which hardware level of autopilot the car has, go to the main menu in the car and select Software. There should be the option to see "Additional vehicle information". Click this and you should see a list of hardware including the Autopilot computer version.
The original electric motors in the MS and MX were called IR and then Infinion but the both of these were fundamentally different to the permanent magnet motor (PMSRM) in the Model 3. There are pro's and con's of both but Tesla decided to move the MS and MX over to the new PMSRM motor in 2019 as part of the 'Raven' update. It's believed the rear motor in the performance MS and MX is still of the older type with just the front motor changing to the PMSRM motor, with the non-performance versions having both motors changed over. As a result of the different technology, some new features are only available on these later cars.
To determine which motors the car has the car has, go to the main menu in the car and select Software. There should be the option to see "Additional vehicle information". Click this and you should see the motors type the car has
Tesla have had a number of MCUs over the years. With the exception of very early screens, there is MCU1 which was used up until the MCU2 launch in March 2018. The MCU2 which has been in production since then although be mindful that this is production date and not delivery date, and that Tesla do not build in strict VIN order. The MCU is totally separate to the autopilot hardware and the performance of one is not dependant on the other.
With the introduction of V11, the MCU2 in the MS and MX started to differ in capabilities to the MCU in the M3 and MY. Tesla have also bought out an new MCU in the 2021 Model S and Model Y, we have named this MCU3 in the table below.
To determine the version of MCU a car has you can use the more information feature on the Software screen within the car.
To determine which MCU the car has, go to the main menu in the car and select Software. There should be the option to see "Additional vehicle information". Click this and if you see against Infotainment processor "NVIDIA Tegra" the car has MCU1. If it says something else like "Atom" it has the later MCU2.
Tesla offer an MCU upgrade to older cars with MCU1. While this gives all the benefits of the MCU upgrade, it also includes an upgrade to the Tesla Autopilot hardware for those cars with HW2 or HW2.5 to HW3 and the features this offers. Cars with the earlier Autopilot hardware, or no autopilot hardware at all get no benefit over the MCU benefits.
Ways you can support tesla-info