If the engine never warms up, it's always in cold mode, therefore the low mileage. You may consider asking a professional about changing your oil more often because of continually running a cold engine. You may be susceptible to oil sludge formation. Not sure.
Ray A.

 

^^^ Thanks for the tip - will keep that in mind and check the oil periodically. What I may do is swap a few days a week my IS for the RX since my commute is 45 miles round trip.

 

I think you got the wrong thread. This is the RX-third generation thread.

 

I also get 13mpg or there abouts. 90% city driving. Lots of 2km trips to pick up the kids. cold weather. I would like to find out some real world numbers from people in Canada who own a 450h with similar weather and similar driving patterns.

 

90% of my commute is mid-range speed highway travel to and from work.
Speed is ranging 25 - 62 MPH (because of morning, evening rush hours), not exactly stop-n-go city traffic.

Round trip is ~40 miles daily, average MPG is 15.0 to 15.2, now at 15.1 since I mixed in a bit more city drive in the past 4 days or so.

Also I felt the car has more power with octane 89, I live in NY, gas stations in NY and NJ typically only have 87, 89 and 93 (only Sunoco has the 4th type octane 91)

Maybe not accurate, but starting with O-93 gas; I've tried all O-rating gas by first driving to a bit below the Empty line and fill the tank with a different grade and feel the difference, all pumped from Mobil except the 91 from Sunoco, and I feel the engine is strongest with O-89

87 is sluggish, 93 felt like the gear is being skipped, etc.

2013 RX F-Sport.

 

So I did some more research and talked with my service advisor about this discussion. Turns out he used to be a regional manager for a chain of gas stations and he was able to add some professional knowledge to the debate.
1. There is a considerable difference in winter formulation that decreases gas mileage for those of us living in colder climates. When I asked what is considerable, he said between 10-20% less.
2. There is also a difference from one brand to another, depending on the additives the company uses. He personally will only use Exxon or Mobile. Interesting coming from someone who knows how gas is distributed from the port to the station. Not to say that getting a no-name brand is bad as they one day could be selling Citgo and another day carry Exxon.
3. Clean gas has as much to do with mileage as any other factor. If filling up you notice the pump is running slow, stop and leave and go somewhere else. That means their filters are clogged and their gas will be dirty. Equates to lower gas mileage
4. I got the whole 9 yards lecture about tire pressure and air filters, etc.
5. He also suggested with every oil change to use a gas cleaner but he didn't try to sell me something. So for $3.00 I tried one of the many types and here are my results.

I ran the tank to nearly empty. Filled up with Mobile and put in the cleaner. My average MPG went from 19 to 23.
I ran this tank empty and filled up at a Cumberland Farms not knowing what type of gas they were pumping that day. MPG drop by 1.

I tried using the recommended premium grade and once again did not notice any change in performance or gas mileage.

 

Suggesting gas cleaners destroyed any credibility he had on this subject.

 

Code red your reply is helpful. It is interesting to see others getting low results from the rx. What I do not understand is Why every other luxury car I have owned has performed closer to its EPA range. How is the rx ranked 18/25 if there are people getting 15 or below with combined city/highway driving that should be getting 20? My loaner from the dealer performed better so perhaps it is an issue with some cars. Or somehow the epa test is exaggerated for the rx. If my car is normal, something seems really off. I still have yet to cross 15 mpg at 5500 miles and both city and highway driving,

 

I bought my Lexus RX 350 2010 with 27K. Only thing I did was to replace air filter with Original OEM size K&N filter, and average city driving is around 19.5 miles per gallon. When on highway, I get around 23 miles per gallon, as I normally go above speed limit, I live in FL.

 

My 2014 RX250 AWD is averaging 23 MPG over 3500 miles. Highway MPG is over 25 and city MPG is around 21, both over the EPA estimate by a good margin.

 

Driving to Florida this month. I hope I get that kind of MPG.

 

I wonder that too, I had a 2010 Toyota Rav4 Sport V6 3.5L
Window sticker says 19/26, I averaged 16.1 - 16.2 mixed city/highway driving, it's better than the RX I have now, and I am sure it's because it has less overall weight provided RAV4 is smaller in size.

If I drive long trip (ex: New York City to Washington D.C.), crusing down the highway at a long distance, the RX gets 16.6 once, but then maintaining 65-70MPH consumes way less gas than stop and go city driving and rush hour highway driving (speed range 25mph - 65mph)

 

Currently around 15-16mpg. 95% city.

 

Just got home from a quick 3 day trip to Rio Rico AZ to pick up a new Welsh Terrier puppy. Round trip was just under 2K miles. Average for the trip was 23.8 with the highest seen since fill up at 26 on one tank. Speeds were up to 95 in the wide open spaces on Hwy 8 bypassing Pheonix. The new 14 Fsport was a joy to drive and much better handeling than the old 08 RX.

 

Sounds similar to me. Except my wife's distance is further. Any city with over 5 mil people you might as well subtract another 10-20% on EPA estimates unless you want to be the slow person making a long commute even longer by holding everyone up lol