Finally had a chance to take the NX for a road trip as we went to central PA for our wedding anniversary.

Of course its been a desert here for the last couple weeks, but the moment I take time off for vacation...rain...rain...and more rain.

So, loaded the dogs up (2 wheaten terriers), all the stuff we'd need, and I quickly found that this car is much smaller than I thought it was. I was rather disappointed considering that 1 tote, 1 normal suitcase, various bags, and a dog bed, and my back window was rendered useless. The entire back was filled up. My boy dog takes the back seat while my girl is a front seat riding dog. Needless to say, the car is much smaller than I thought. Our previous search for a truck came back into my mind, and its a true shame that the Tundra is so far behind the tech curve compared to the American offerings, otherwise I'd probably have a Tundra and would have had more space...

Regardless. Drove through moderate to heavy rain the entire way down 79 and 80. Car did fine, rather comfortable though the storms and with it in ECO and about 74-75mpg the entire time, it averaged 24.7 mpg. Its a little disappointing, but as a I put in the fuel economy thread, it proves my theory that the turbo usage really dominates the fuel mapping for this car.

On the highway I had one major complaint, the radar is just plain terrible. Whoever decided on the programming on that radar should be pulled out of their office, and just beaten to death. Its terrible. I am a person who likes to just turn cruise on and GO. Never touch the gas pedal and just let the car lead the way. But with this radar....75...down to 69...you MUST change lanes 100ft behind (even if you vary the range) the person or else the car wants to slow down. And the worst...if someone pulls out in front of you while you're in the left lane.....BRAKES!!!!! Absolutely ridiculous and probably the most pathetic option I've ever seen in a car.

Now, the cabin was in the backwoods, which was even worse considering the storms that had gone through the area. The car did fine with those type of road conditions until we stopped at the cabin one evening and I put the car in park and heard SCREECH coming from the parking brake. I set and reset it multiple times to confirm my thoughts The parking brake was all gunked up. I was driving on dirty roads for 2 days and the parking brake is already full of crap? Are you serious? What if I lived on roads like this?

Either way, I took a hose and sprayed the rear calipers down and after 2 more drives the sound of the parking brake setting and resetting started to sound more like normal again.

Another odd occurrence was we were ready to leave for dinner one evening and I had my driver side door open to listen for the parking brake. The car started normally except my screen never came on. Confused, I shut my door, and the moment I shut my door, the screen popped on already on the GPS display. wtf....

Drove home though light rain yet again, and driving in the same conditions, against the slip stream I got about 24.3mpg.

This was probably the dirtiest and grossest the car has ever been. After coming back I spent 3 hours cleaning the car and found several great locations where rust will begin in the future. So that will be a joy to keep track of as time goes on.

Not much else to say. The mpg was ok, not great, but I never cared about mpg to begin with. The radar is ridiculous, and at least the ride is comfortable haha.

 

"On the highway I had one major complaint, the radar is just plain terrible. Whoever decided on the programming on that radar should be pulled out of their office, and just beaten to death. Its terrible. I am a person who likes to just turn cruise on and GO. Never touch the gas pedal and just let the car lead the way. But with this radar....75...down to 69...you MUST change lanes 100ft behind (even if you vary the range) the person or else the car wants to slow down. And the worst...if someone pulls out in front of you while you're in the left lane.....BRAKES!!!!! Absolutely ridiculous and probably the most pathetic option I've ever seen in a car. "

My HS250 was exactly the same. I learned to deal with it but the progrmming was brutally set to nanny mode. On the other hand, I had a Mercedes CL65 that had the most wonderful seamless smooth radar cruise. Now I know they'tre all totally different cars but I have to believe that the Lexus version has gotten little attention and little priority in the engineering dept. I know they can do better. I would not order this option on a Lexus again until it's fixed. I actually consider the system design to be broken.

 

It is considered a compact SUV, by the way.

Is this a hybrid? If not, then the vehicle is rated at 28 MPG highway. Typically, EPA estimates are higher than actual, so I would think you did pretty well--especially since it was loaded down with a lot of cargo and you were driving in inclement weather.

 

Two additional thoughts ...

1. Fuel economy is adversely affected by heavy rain. Losses at the tire/road interface (effectively, the car is a water pump) and increased total wind/H2O resistance are the key culprits.

2. Using the 1 car length per 10 mph rule, 100 ft spacing is about right for safety at 65 - 70 mph. The adaptive cruise feature is not going to be a favorite of tailgaters.

 

Is that what CUV means..... lol

Yes, I'm well aware, but I didn't figure how quickly the room would be taken up.

And no, its not a hybrid, but I am able to easily get 28-30 mpg on my 23 mile drive to work daily by utilizing little boost. I'm still looking for someone who has a key that can allow me to look at the fuel mapping.

 

1. Your first point will usually only seen when going to a wide tire. A 225mm tire is not that wide and is typically considered a narrow tire (for winter applications). The rain had little effect compared to the amount of utilization of the turbo in order to keep that little 4 banger going against weight and air resistance. Your point is completely valid in instances like my Camaro with 295s in the back. When it rains, I have little traction and I feel the car pushing thru rain.

2. 1 car length per 10mph is a silly driver's school rule. The problem with this system is several things:

First - The system will begin to make you drop speed FAR away from the car in front of you, which will then leave you vulnerable if you try to pass someone. Example....going 75mph and you catch up to a car (back about 60-70 ft) and the car feels the need to begin lowing down to 69mph. You make the decision to pass this person and as you move into the left lane, you are now down 6mph which is now causing a safety issue with everyone coming down the left lane because yoru car has to reaccelerate which slows and entire lane down.

Second - Driving in the left lane, passing cars on the right, when someone pulls from the right lane in front of you to go around the car in front of them and the car feels the need to slam on the brakes. Example, you're going 75mph and someone pulls right out in front of you from the right lane at ~69mph, the car feels the need to SLAM on the brakes (well below 65mph) so it can rebuild the distance. This is ridiculous, not only does it cause unneeded wear and tear on my brakes, but it also creates a safety risk for the person who was keeping pace behind me in the left lane who just got the brakes slammed on them.

I don't need an education on "tail gating", this is a **** poor design by Lexus. I stay back from people because I prefer to avoid rock chips and find that 90% of the people I drive around, shouldn't be driving at all, or think they are professional race car drivers in their Prius....

The radar needs to have several more bias and gain controllers to retard the impulses of the system. In the first situation, the car should determine how much you're gaining on that car and begin to cut speed by 1-2mph until you have surpassed the length determined on your dash, that way you have the ability to change lanes before it begins to change speed. For the second instance, the cars needs to check its speed, look at an algorithm to compare the difference in speed between it and the new incoming object, realize it will take time to recreate the "needed distance" and gradually low down. There should also be an integrated timer based on speed for how long the car takes to recreate the separation. The separation shouldn't be instant, or within 100ft. It should take 1/2-3/4 mile to rebuild a distance that was lost. This brake slamming is ridiculous.

 

Breakthrough in fuel efficiency!

I haven't had problems with this in the IS or NX. What I will say is that highways in the US are much more congested than in Canada (especially Western Canada). When I drove down to California a few years ago, I have to say at least 75% of drivers do not leave safe following distances (what I consider to be the 2 second rule). Unless the car cutting in front of is literally RIGHT in front of me, I find the radar cruise to be pretty "adaptive" (pun intended). I will admit the Lexus system on the cautious side but setting 1 is pretty comfortable and importantly, safe. I would consider setting 2 to be the "driving school" approach.

 

Trying to get a good overall average between cars since after all my Camaro work is done next year...I'll probably get somewhere between 7-8mpg around town lol

 

Does the NX have a way to disable the dynamic cruise?

We have radar cruise on our RX, though our experience has been mostly positive. On the RX, you can disable the radar cruise and go into constant cruise (aka normal cc) mode. The NX may offer the same thing.

 

Yes, the Dynamic radar cruise control can be switched off into regular (constant speed) cruise control mode.

According to the NX manual:
I'm curious though Swacer, have you tried lowering the Radar Cruise Control sensor distance control to see if it helped the situation?

 

1. All four of my standard issue Lexi have lost (loose) a 1+ mpg in medium to heavy rainfall. Unless one tries to rewrite the laws of physics and the sub-disciplines of aerodynamics and hydrodynamics, it must be so.

2. Thou does protest too much. For my area and driving habits, the dynamic cruise has worked pretty smoothly so far in tracking down and in recovering speed. I reiterate my belief that the 'nanny cruise' is not going to be a favorite feature of the aggressive driver and the tailgater.

We'll have to agree to disagree.

 

28 mpg EPA highway is tested at ~50 mph. So 24 mpg at ~75 mph in the rain is spot on.

Swacer, you mean to tell me you weren't able to cram in 28 cu ft a-la mulch?

 

If this is true (and I'm yet to check it), I could hug you lol

And yes, I have tried lowering it. I hate 3 dashes, 2 dashes is what created the situation I describe, and 1 dash I feel makes you drive too close in which you'll get chips.

 

Yeah, I was only just saying to me its a bit interesting to have a car that does worse on the highway than it does on backroads. That's all.

And no, I wasn't as good of a packer was you were! I didn't optimize all the space. Probably wouldn't be able to fit as many bags as you did lol

 

You and I seem to have similar driving styles. This option is the ONLY option that ours didn't have and judging from your experience, I'm SO GLAD we didn't get it. $900 in the pocket.