Top speed limited in Lucid Air

[Volund]

Any idea why the top speed is limited for the Lucid Air (except Sapphire)
They did the stability test to 235 mph+ 7 years ago.
So how come all of our cars are speed limited software to 168 mph?

 

[joec]

Any idea why the top speed is limited for the Lucid Air (except Sapphire)
They did the stability test to 235 mph+ 7 years ago.
So how come all of our cars are speed limited software to 168 mph?

Maybe because dead customers are not repeat customers?

All joking aside, lots of cars are limited in speed electronically. Not sure of the reason.

 

[xponents]

Any idea why the top speed is limited for the Lucid Air (except Sapphire)
They did the stability test to 235 mph+ 7 years ago.
So how come all of our cars are speed limited software to 168 mph?

Most german sedans are tested to ridiculous standards that they cannot hit. For example, the VW phaeton was requested by Ferdinand Piech to go 186 mph while being stable and maintaining a good AC temperature. This is despite the fact that it is limited to 155 mph.

I believe the limitation to 168 mph is therefore of power, and critically tires. Tires are likely the main factor, as you need special tires when you are going above around 170 mph. This is for example why the Rivian R1T is limited to around 115(?) mph as its tires could not handle a higher speed, even if the powertrain can. With Lucid's low resistance and low profile tyres, I suspect the effect is exacerbated causing it to be limited to 168 for tire safety reasons. In addition, testing at higher speeds just makes sure that the car is aerodynamically sound, so even if a customer does the stupidest sh*t ever by limiting the remover and going full send stock, it can handle it(apart from the tyres, which will probably blow at 180).

https://www.tiresplus.com/tires/tire-buying-guide/tire-speed-rating/ this supports my argument as if you scroll down, "W" rated tyres are limited to 168 mph. Could somebody check if anything is mentioned of a speed rating on the tires?

To me, having 168 is already very impressive, knowing that it can handle well in excess of that speed and STILL be stable and considering its low rolling resistance, low profile tires. As soon as I get a license, I would definitely love to see how silky smooth the Air is at these speeds on a runway.


TL;DR: Most important reason is tyres.

 

[suchluke]

+1 for tires being limiting factor.

 

[Halodde]

Any idea why the top speed is limited for the Lucid Air (except Sapphire)
They did the stability test to 235 mph+ 7 years ago.
So how come all of our cars are speed limited software to 168 mph?

My first thought was the same thing that @xponents said above. I think back in the '80s OR '90s the German auto manufacturers voluntarily agreed to limit their cars to a top speed of 155 mph and in exchange for that the German government was not going to put a speed limit on the autobahn. If they had not voluntarily limited their cars, the German government was going to implement a speed limit at different points on the Autobahn.

But having said that, I assume they could have just software Limited the European models to 155 and left ours alone. So the answers above are probably more accurate in that it's a safety issue

 

[suchluke]

Here is a chart for Tires Speed Rating

 

[xponents]

My first thought was the same thing that @xponents said above. I think back in the '80s OR '90s the German auto manufacturers voluntarily agreed to limit their cars to a top speed of 155 mph and in exchange for that the German government was not going to put a speed limit on the autobahn. If they had not voluntarily limited their cars, the German government was going to implement a speed limit at different points on the Autobahn.

But having said that, I assume they could have just software Limited the European models to 155 and left ours alone. So the answers above are probably more accurate in that it's a safety issue

Yes, that was around the time that the BMW and Mercedes DTM rivalry was going to new bounds, making their production models(190e EVO and M3) ridiculously fast. They therefore limited their speeds to stop the battle for supremacy getting unsafe.

However, this gentlemen agreement(which by the way, japan also had, story for another time) eventually expired, as current cars like the M5 are limited to 190(this does need the M driver package) which obviously violates the agreement. Most of their models without the M drivers package and that can handle it do have 155 mph. I do not follow Mercedes much, so I do not know how things are going on that side.

(by the way, porsche almost never gave a sh*t, they just kept going through the 1980s-90s)

 

[joec]

Most german sedans are tested to ridiculous standards that they cannot hit. For example, the VW phaeton was requested by Ferdinand Piech to go 186 mph while being stable and maintaining a good AC temperature. This is despite the fact that it is limited to 155 mph.

I believe the limitation to 168 mph is therefore of power, and critically tires. Tires are likely the main factor, as you need special tires when you are going above around 170 mph. This is for example why the Rivian R1T is limited to around 115(?) mph as its tires could not handle a higher speed, even if the powertrain can. With Lucid's low resistance and low profile tyres, I suspect the effect is exacerbated causing it to be limited to 168 for tire safety reasons. In addition, testing at higher speeds just makes sure that the car is aerodynamically sound, so even if a customer does the stupidest sh*t ever by limiting the remover and going full send stock, it can handle it(apart from the tyres, which will probably blow at 180).

https://www.tiresplus.com/tires/tire-buying-guide/tire-speed-rating/ this supports my argument as if you scroll down, "W" rated tyres are limited to 168 mph. Could somebody check if anything is mentioned of a speed rating on the tires?

To me, having 168 is already very impressive, knowing that it can handle well in excess of that speed and STILL be stable and considering its low rolling resistance, low profile tires. As soon as I get a license, I would definitely love to see how silky smooth the Air is at these speeds on a runway.


TL;DR: Most important reason is tyres.

Today I learned…

Thanks.

 

[xponents]

Today I learned…

Thanks.

Out of that whole essay, I find the Phaeton and most of Piech's work particularly fascinating. I'd highly recommend doing a quick wikipedia browse of that and Piech's other child, the Bugatti Veyron!(which by the way, also needs 42000 a tire set to hit its top speed. this almost caused a breakdown within Michelin as they could not figure out how to build it. At the end, they did for an exorbitantly high price and had to glue each tire to the rim. even then, the tyres have to be replaced every 18 months, the rims have to be replaced after 3 tyre changes, and it cannot last 15 minutes at its top speed without blowing.)

 

[hmp10]

So how come all of our cars are speed limited software to 168 mph?

Most modern automakers electronically limit their passenger cars to the speed rating of the factory tires.

168 mph happens to be the speed rating of W-rated tires. The Lucid is delivered with Y-rated tires of 186 mph. However, the Lucid is exceptionally heavy for a car of its size, so I suspect Lucid dialed the electronic speed limiter back one step just to be on the safe side from a liability standpoint, especially as customers who need more winter traction might mount snow & ice tires on their cars, which typically carry lower speed ratings.

 

[Volund]

Maybe because dead customers are not repeat customers?

All joking aside, lots of cars are limited in speed electronically. Not sure of the reason.

Only thing that really piqued my interest was because the Model S is limited right at 200 mph.

So I was just wondering why such a large limitation on a sports car Lucid is basically trying to hit performance numbers on? Even the air performance.

The tires makes sense. But does that mean the Model S has higher than Y?

 

[xponents]

Most modern automakers electronically limit their passenger cars to the speed rating of the factory tires.

168 mph happens to be the speed rating of W-rated tires. The Lucid is delivered with Y-rated tires of 186 mph. However, the Lucid is exceptionally heavy for a car of its size, so I suspect Lucid dialed the electronic speed limiter back one step just to be on the safe side from a liability standpoint, especially as customers who need more winter traction might mount snow & ice tires on their cars, which typically carry lower speed ratings.

I was wondering what tires the Lucid has, thank you for the confirmation! Now I wonder, what tire rating does the sapphire have?

 

[joec]

The tires makes sense. But does that mean the Model S has higher than Y?

maybe. Or maybe Tesla just doesn’t care if you blow your tires.

 

[xponents]

Only thing that really piqued my interest was because the Model S is limited right at 200 mph.

So I was just wondering why such a large limitation on a sports car Lucid is basically trying to hit performance numbers on? Even the air performance.

The tires makes sense. But does that mean the Model S has higher than Y?

Wait wait wait, the Model s is not 200 mph. That is only the plaid with the track package. If you do not get the track pak(which includes new rims and tires), it is still 162 which is lower than the Air. In addition, I believe the Tesla has a lower rated tire and is FAR, like dangerously far from being aerodynamically stable.

 

[hmp10]

But does that mean the Model S has higher than Y?

Our 2021 Model S Plaid was delivered with Y-rated Michelin Pilot Sport 4S's.

 

[Bus Driver]

Wait wait wait, the Model s is not 200 mph. That is only the plaid with the track package. If you do not get the track pak(which includes new rims and tires), it is still 162 which is lower than the Air. In addition, I believe the Tesla has a lower rated tire and is FAR, like dangerously far from being aerodynamically stable.

Exactly. I’ve never approached speeds of 168 mph in either the Air GT or our former Tesla Model S. But I’ll tell you this much - At 130 mph, the Air GT tracks with the unerring, rock-solid stability of a French TGV high speed train. The Model S twitched and floated albeit to a mild degree, but enough to leave one a little disconcerted.

As an aside, at those speeds wind noise increased in my Air GT for sure, but the Model S, with the sashless windows being sucked off the cantrails, simply ROARED.

 

[hmp10]

Exactly. I’ve never approached speeds of 168 mph in either the Air GT or our former Tesla Model S. But I’ll tell you this much - At 130 mph, the Air GT tracks with the unerring, rock-solid stability of a French TGV high speed train. The Model S twitched and floated albeit to a mild degree, but enough to leave one a little disconcerted.

As an aside, at those speeds wind noise increased in my Air GT for sure, but the Model S, with the sashless windows being sucked off the cantrails, simply ROARED.

Our experience with the two cars (Air Dream and Plaid) exactly.

 

[Snafu]

Has anyone noted their car limiting the speed when under 90 mph (and driving completely normally otherwise?)

 

[Volund]

Ths

Wait wait wait, the Model s is not 200 mph. That is only the plaid with the track package. If you do not get the track pak(which includes new rims and tires), it is still 162 which is lower than the Air. In addition, I believe the Tesla has a lower rated tire and is FAR, like dangerously far from being aerodynamically stable.

Thanks for that correction, seems I may have had a misconception. And that's true, if the tire doesn't even support the speed, it's just a hazard at that point

 

[xponents]

Ths

Thanks for that correction, seems I may have had a misconception. And that's true, if the tire doesn't even support the speed, it's just a hazard at that point

I think the tire supports it as @hmp10 stated(not sure about smaller wheels though) but they do not support 200 mph by any stretch. The aerodynamics and brakes also leave much to be desired. Teslas marketing around 200+ mph has been deliberately misleading IMO.