Hi all,

I am looking to purchase an RX soon as a daily driver. I’m drawn to the hybrid for fuel economy and I like the driving experience a little more. I live in the Sacramento valley so most of my driving is flat. However, I ski frequently so I am driving up I-80 to Truckee most weekends in the winter. When the roads are clear, it’s normal for the flow of traffic to be at 65-70. I’m hoping someone can give me some insight into how the 450h handles extended uphill grades, particularly at elevation. My main concern is having sufficient power once the traction battery is depleted. Any insight is greatly appreciated.

 

Not a concern. Traction battery will never be allowed to be depleted as the hybrid system will just prioritize charging rather than using the electric motors to assist in acceleration. The V6 itself has plenty of power on its own, and at high speeds, the electric motors are seldom used anyway since they are more efficient for low speed asists.

I've done plenty of runs up the local ski mountains here, and while I haven't done as high as Truckee (looks like 5800 ft), I've done a few runs up the Coquihalla pass (> 4000 ft) at 120-130 km/h (80 mph) easily.

The main 'concern' for the hybrids are actually not the uphill climbs; but the descent part, especially if you have a long downhill slope. To prevent overcharging the batteries, the hybrid system will fire up the ICE to try to burn off the excess charge. At the same time, I've noticed it will alternate between regen and the physical brakes if you need to use the brakes to slow down the long descent. When this happens, the brakes appear to pulse, similar to the feeling you get when your rotors are warped. It's a little disconcerting at first, but you eventually will learn to control it.

 

Fun to drive my 450 in/around Breckinridge, Grand Lake, Leadville, etc.

 

Living in S.W. Fla. I do not anticipate any problems with long uphill/downhill runs. The tallest 'mountain' here is "Mount Trashmore", produced by recycling local garbage(about 100ft. above sea level).
I have an order in for a 2022 RX450h scheduled to arrive in Dec. I owned and totally enjoyed one of the first RX350 models to enter my area(GPS, backup camera were top of the line tech at that time). Really looking forward to getting back into a Lexus.
With the regenerative braking, is there a braking action caused by just lifting the foot from the accelerator to coast into a relatively flat drive up to a stop light?
I normally try to arrive at red lights as they are turning green(much to the dismay of my wife who continues to maintain speed to the stop, then 'hit the brakes' as she arrives).
I hope this is not a hijack of your original thread, just trying to get a feel for driving what I believe to be the next iteration of the Lexus.

 

I have a 2018 450 HL and I live in the Colorado mountains. We have a home in Denver and one in Grand Lake. The route takes us over some very steep terrane. On I70 leaving Denver, there is a 5 mile 7% up hill grade, which the RX does perfectly at 70 mph. I think the speed limit is 65. The next steep part is Floyd Hill and it too is 7% for about two miles and on this downhill segment, I put the car in 5th or 6th gear to keep the speed under 70mph, and not use the brakes. The next steep segment is Berthoud pass, which peaks out at 11,300 feet. The speed limit is 45, but at the risk of a ticket, you can go as fast as you want up hill. I have 43,000 miles on the RX and because of the CVT, it is the first car I have owned that has not had brake fading due to them getting hot on the down hill sides. The CVT is perfect transmission for steep road descents, it does all the needed braking or slowing. I have need had an issue with power, and so I just leave it in Normal as opposed to Sport mode

 

On my 2010 450H I think the engineers tried to make the car feel as conventional as possible. Thus, lifting your foot off the accelerator does result in a very slight braking and you can see the power gauge needle move down into the charging zone about halfway. Just a very light application of the brake pedal puts the needle at the bottom, implying a maximum regen. In my 4WD car "maximum" regen does not dramatically slow the car down as it would in (from what I hear) a Tesla. But it's a fact that even this level of regen braking has a dramatic effect on extending brake pad life.

 

The best think about the hybrids is that on downhill even at 10% you set the cruise control at a specific speed and the car keeps that speed and does not allow it to increase speed. Not even by 2 mph.