I'm currently averaging between 28-29 in mixed driving on premium gas in my 2016 RX450h F Sport. On recent trips of 90 miles each way at 55-60 mph cruise, I averaged 29.7 in Normal mode (I never use Eco, and rarely use Sport mode). I always use premium gas, and here in Oregon, we get E90 (10% ethanol). I think starting around the beginning of April, the refiners will switch to their summer blend, and I expect my mileage to increase to 31+, which is where it was until about the beginning of November, when I think the refiners switched to their winter blend. Ethanol has less energy than gas so the more ethanol in the gas, the less mileage you get, and I believe Lexus approves as much as 15% ethanol for the 450h. I'd suggest checking to see how much ethanol is in your local gas (it should be clearly labeled on the gas pump). 15% ethanol will be labeled E85 and will produce less mpg than E90.

 

I would love to see our government STOP putting ethanol in our gas.

 

I'm driving 2017 RX450H for past 2 weeks and have driven 700 miles, so far I'm averaging 27.1 MPG. Lexus claims 30MPG combined for RX Hybrid but don't think I will ever get 30 MPG.

 

On my past three tankfuls, i have been averaging around 30-32 MPG. This is a mix of street and highway. When there is a lot of stop and go traffic on the highway, my mileage goes up. One day traffic was so bad I managed 47.5 MPG.

I have learned to ease of the accelerator to turn off the engine and run on battery on the city streets. Basically, I get up to the street speed limit, then release the throttle a little, the engine turns off, and I just barely keep it at the max battery without turning on the engine.

 

Thought I'd post an update on RX 450h mileage. With about 4,800 miles on the clock, my car is averaging around 27 mpg. That's not great but I've noticed two factors that have the most profound effects on gas mileage. Those are temperature and speed. The car only gets 91-93 octane from Costco, Shell, BP, and Exxon (Top Tier stations).

First, temperature. From what I can tell (not scientific at all), the RXh does not like cold temperature. This is something all hybrid drivers have reported for various makes and systems. At temperatures below 45 degrees Fahrenheit I'm seeing around 25 mpg on the highway. However, at 50 degrees Fahrenheit and and above, the car reaches 27 mpg. 28 mpg (EPA rating) and above appears to be only possible when temperatures are over 60 degrees Fahrenheit. That said, I am not sure how much A/C effects the mpg, so I will have to see about that in the summer.

Second, speed. Obviously the car gets great mpg in the city. I've seen up to 40 trip average mpg with a peak of 50 mpg at one point in a trip. At speeds less than 42 miles per hour, the ability to keep the car in electric mode is very easy. Most of the roads around my house are 45 miles per hour and at this speed, it seems the car prioritizes the efficiency of running the engine and using the electric motor as an assist. Looking at the highway, speed plays an obvious role. At 55 miles per hour (where most engines are the most efficient), reaching mileage of 30+ is simple. While driving on country roads at 55 miles per hour, I've averaged 36 mpg. However, it the freeway at 65 miles per hour and more and the MPG drops dramatically. With radar cruise active, 35 degrees Fahrenheit, at 70 miles per hour, I usually see 27 mpg. At speeds of 75 miles per hour, that drops to 26 mpg. And at 80 miles per hour, that drops to 24 mpg! These were discovered from a recent road trip from Ohio to Texas.

Obviously, these values are not scientific at all, but I thought I'd share my experience. Nevertheless, I'm really impressed with the mpg I'm getting. Especially considering my 2007 Infiniti M35x is getting 21-23 mpg in the highway and my 2008 Accord Sedan V6 is getting 25-28 mpg on the highway.

 

By adjusting my acceleration style and trying to get car run as much as in battery in local roads I'm able to get 28.5 MPG now (1600 miles so far). My previous car 2008 E350 was averaging 17-20 MPG so I'm pretty happy with the RX performance. Also, it much quieter than my prev E350.

 

Just on my first 1000 miles and I am getting 28-29 at 60-65 mph. City is always over 30, it averages about 31, sometimes 32.

Very happy with the performance.

 

Just had my first trip in my new 2017 450h. Indicated average MPG was 28.9 for a 220 mile trip that was lots of stop and go on the way down (Friday before memorial day traffic) and lots of time at ~65mph on the way home. Great!

Also, this is my first car with dynamic cruise control and let me just say- WOW! I drove 2 hours home and didn't have to touch my pedals for more than a couple minutes tops. This was in medium traffic; I set it at 76mph and only got over 70mph a couple times and the rest of the time it just held in the pack at a perfect following distance. This is my new favorite car; can't wait to take many more road trips in it!

 

You guys with your 450H, great mileage, quiet performance, no hesitation, etc....I don't like any of you! Just kidding but the rx350 is getting replaced by a 450H...soon if my wife lets me! haha

hey Greg you have two, that's one too many!

 

FastFord, higher mileage is certainly a perk but not the only reason to go hybrid. Some you've already mentioned. Add more HP and lower maintenance cost, among other things. Have your wife drive the 450h and maybe she'll let you get one.

 

Kidding about my wife, she doesn't care what I get. I drive mostly city and think a few less stops at Mr. Gas-station would be great! I think I should wait at least one year before I get another one!

 

Sounds good. The gas station visits are every three weeks for me Sure, I could easily stretch it to monthly. But I prefer not to go too far below half a tank. Also, achieving better mileage is easier than the previous gen 450h without sacrificing power. Eco mode is like power mode on my old RXh. In fact I keep eco mode on year round to help regulate speed, LOL! Some food for thought.

 

I say wow often in my 2017 450h, f sport....love the car. The hybrid system is so much better than the car I traded it, a 2008 rx400h. If you want a fully loaded car, (I mean fully loaded with all factory options) then the hybrid is less than $3000 more. WIthout much effort I am getting about 27-28 mpg each tank. And the cvt is great, no hesitation in normal or sport\sport+. I also have a 2013 corvette and I never drive it, the lexus is just a fantastic car.

 

Impressed on the lack of gas needs. How many miles do you average in a week or month. Mostly city driving?

 

Greg, the daily commute is about 12 miles round trip, all city driving at or below 40 MPH. Half of it consists of hills. On the weekends, sometimes I'll do a bit more driving. It's less than 100 miles a week. Infrequent road trips bump it up above that. At 13 months. I have 6,000 om the odometer and am averaging 28+ MPG. Mornings are still on the cool side. The heated seats are turning on, one dot. The mileage will go up a few MPGs soon. There is one disadvantage with the infrequent gas station trips, losing out on the credit card incentives for using the card and/or at a gas station