cc16ue

iTrader: (1)

Does anyone know if the 3rd generation RX has a speed governor?

slawless

My 2014 is 112 mph. the new 2016 is 115 mph.

MellonC00

My friend tells me that he tried to go above 105 mph but he couldn't. It's like there was a wall of wind blocking the car. Not sure if it was the limiter or lack of power at that speed.

SteveCraig

Speed limiter essentially limits the engine RPMs. High gear at max. revs = top speed.
Only way to fool it on a modern car is with a stick shift.
We bought a new V6 4 dr, Accord back in '05 after seriously looking at the 2 dr. 6 speed coupe. That car was a virtual street legal rocket-ship.
Good friend of mine was the Service Manager at the local Honda dealer. He called about 2 months later, the 2 dr. sold just after our 4 dr. purchase & was towed in.
Owner's son took it out for some tuner racing. Had it up to a very high speed & needed to slow down in a hurry.
Missed a gear or two on the way back down & pushed the engine way past the safe limits.
Owner brings it back demanding a new car as the product had evidently failed for no reason !
ECM showed the dirty little details just before the owner had a heart to heart talk with her son.OUCH.
In 2005 dollars I think the top-end was about $ 4K + 15 % tax.

cc16ue

iTrader: (1)

My "friend" tried to go above 100 and it wouldn't go past 98. My "friend" could down shift but the speed wouldn't go any faster, so not sure if the ECU limited the car to not go beyond that speed. Anyone else's "friend" experience similar scenario?

lexus114

um, i wouldn't want to go much past 90 in these cars...just sayin.

11bravo

I've been to an indicated 105 in our '13 RX. Car was rock solid...don't know why anyone would fear going "above 90" in these cars, unless they would fear doing so in other cars, which I can understand. High speed is not for everyone.

At 105, there seemed to be more left, and no rev-limiter activity. It was fast enough for me, considering a citation at that speed would be around $800.

vlad_a

This guy claims it is limited to 112:
https://www.clublexus.com/forums/rx-...ahn-sucks.html

11bravo

Vlad, I believe he is likely correct. Most passenger, SUV, and truck vehicles have a governor. This is more to protect the manufacturer from liability suits than for any other reason. Producing a "normal" vehicle that is capable of exceeding 120 MPH without limiting it to a lower speed could be claimed to be an unsafe practice. Most high-performance cars (Corvette, Porsche, Mustang Cobra, etc) do not have speed-limiters because it is a given that anyone buying such a car knows it is capable of high speeds, and assumes a certain amount of responsibility for the operation of the vehicle. That does not prevent lawsuits, but has been an effective defense and deterrent.

cc16ue

iTrader: (1)

You would think that would be true but look at Paul Walker's family. I feel bad with him and everyone involved about that tragedy, but to blame Porsche for his death and not the reckless driving and the condition of the road...

F250

Denial of personal responsibility!! We live in a world where too many people really believe that spoons make people fat and pencils misspell words.

11bravo

The lawsuit brought by his daughter is based on the fact that the Carrera GT does not have the automatic stability control system that other Porsches have. High performance cars that do have the "nannies" usually have switches to turn them off. That switch is another block against liability. If the driver loses control with the switch "on", it is deemed that he was simply driving too fast for conditions, and no fault of the vehicle. If the same happens with the switch "off", it is deemed the driver made the decision to disable the very thing that would have saved his life.

I do not blame the car makers at all for this. They have to protect themselves from our court/legal system, which is guilty of removing personal responsibility from humans.

And that is why there are speed limiters on non-high-performance vehicles.

vlad_a

This may be more related to a "gentlemen's agreement" that some manufacturers had adhered to in the past to prevent government regulation from stepping-in.
That's why many German high-performance cars are/were limited to 155MPH (250KPH):
http://www.autoblog.com/2005/07/14/m...55-mph-limits/
http://www.thetruthaboutcars.com/200...hall-be-known/
Similar agreement was in Japan to keep HP for domestic vehicles below 276HP to avoid a horsepower war between manufacturers:
http://www.caranddriver.com/news/jap...-pact-car-news

That all lasted until marketing stepped-in. Germans started to bundle higher speed governors with their "sport" packages.
Lexus, on the other hand, never advertised their speed governor settings. However, they have been generous.
For example, while 3-series BMW was limited to 130MPH, my IS300 topped out at 147MPH.

lbzya

So if the governor is set this low on the RX's, why the V rated tires?

mkeeney

Because Michelin is able to charge a lot more for the same tire if there is a V on the side instead of an H. That's the real reason. For many people, a higher speed rating equals a better tire, so Lexus and Michelin are just playing to the incorrect notions of the average consumer.

Also, the 3rd gen RX is indeed limited to 112 mph. It is based on the electronic speedometer, not engine rpm. There is no way to trick it by changing gears, because the car still knows what gear it's in and how fast it's going. The fuel injectors cut out until the car drops below 112 again.