I recently rented a 2018 Ford Escape and commented to a friend, with a 2017 Porsche, that the Escape had a fuel cutoff thing that turned off the engine at red lights. My friend insisted that all 2017 cars have that, or at least the higher end ones like my Lexus that certainly has it. I can't find it. He called Lexus and the service lady said that some RXs have it and some don't...it's an option. So he asked her where the switch (I think they all are to have a switch to shut down the mechanism) is...and...as I suspected...she didn't know. Which implies to me that she really had no clue.

Does my car have this? Do all newer RXs? Is it optional? Or is it non-existent altogether, as I suspect, on the current bodystyle RX350?

 

I’ve never heard of that, at least not for the US models. The 450h does this of course, but I don’t think the 350 does.

 

The RX350 does NOT have the Start/Stop feature. The RX450h all do.

The "service lady" was right.

 

Except for the 2017 Highlander, none of the other Toyota/Lexus vehicles have the Engine Stop/Start feature (at least in N/A). The Hybrids have a variation of it obviously, but they don't use a regular starter; and don't start up the engine as soon as you let go of the brakes.

Whether this is a case of Toyota not wanting the non-hybrids to compete in fuel efficiency (unlikely), or the usual conservative engineers at Toyota not trusting the long-term reliability of the Stop/Start feature (most likely)... we may never know. But we will likely see the trickle down effect of the Highlander's system in future Toyota/Lexus vehicles.

 

I see. She was right in that the hybrids have it and the non-hybrids do not. She did not understand that the "option" she was referring to was the hybrid, but technically she did get it right. The correct answer should have been that the hybrid RX has this and the non-hybrids do not, in any configuration or option package. Got it!

 

In Australia the NX has stop/start but not the RX - you don't want it, it's a gimmick. Save fuel they say, maybe slightly but the extra cost and wear on other engine parts over time will negate any fuel savings.

 

I agree. I've never driven a car like that, but I think it would annoy the heck out of me.

 

All versions of RX 2016/2017 sold in Canada don't have this feature. It is actually not very useful because as mentioned above, the cost savings and environmental advantages are minimal compared to wear issues.

 

I hate Stop start and some don't even allow you to disable the feature. Non starter for me.

 

I'm great full that the RX doesn't have it. If it did I'd take it back to the dealer to disable it like I've done to all my other cars, bmws, audis, etc...

 

I was considering a Q5 before buying the RX and the stop & go engine was the main reason not to go with the Q5. A gimmick if ever I saw one.

 

Test drove a jeep grand Cherokee summit, same shut off, take your foot off the brake it restarted. I think it had a switch to disable the system. Very noticeable.

This was implemented by manufacturers because the city milage test included stop and go scenarios,
Guessing this tech might go away, since the regulations on milage are or have been removed in the states.

https://www.nytimes.com/2016/04/08/a...it-or-not.html
Explains the reason for start stop
https://www.fueleconomy.gov/feg/fe_test_schedules.shtml

 

How much gas does this technology save vs. how much additional wear and tear is happening on the engine?
I did not like it in both a BMW and Mercedes I drove. The vibration after each start was noticeable. Both were 4 cylinders. I dont mind start stop in Toyota hybrids. I think toyota/lexus has mastered making it almost undetectable. Merc and BMW could do a better job.

 

10 percent from the article if i recall, i just skimmed it.
Toy is very smooth on the hybrid start, no doubt.

 

The RX-450 hybrid transmission has a starter and electronic gear "ratio" built in. It's design is nothing like the Ford or other transmissions on the market. The action of the 230+ volt starter on the RX-450 is darn near undetectable. Check out the videos on YouTube that show how the starter is integrated into the transmission. On my RX-450 the startup or re-start occurs in a very small instant at much higher RPM's than a conventional starter. You really have to drive the Lexus Hybrid to realize how seamless the engine stops and starts are. The transmission is also super smooth with none of the rubber band CVT effect. This is not your father's Oldsmobile!