julieu22

I bought a 2011 RX w/50k miles in December of 2014 and am consistently getting 13.7-14.2 mpg. I mostly drive in the city, but do small stretches of 50-60 miles per hour w/little change on the computer. Last week I took a trip on expressway and the mpg's never went above 14.5 mpg. I live in Illinois and it has been very cold here but I still think this is horrible mileage. I do not "gun" it; in fact, I stay within the green "eco" light 95% of the time.

LexCareSC

The Fuel Economy testing by the government estimated the MPG's for this model at 18/24 city/highway. This was done in a controlled environment with limited conditions. The circumstances in which you are driving may affect the MPG as well. These things would be items such as mountain driving or rough terrain, using the A/C or Heater while driving, or towing. These are just some examples that may affect the MPG's.

If you feel the MPG's are off in the vehicle, we would suggest having a fuel consumption test done to verify that there is indeed a problem. This would allow any technician to be able to attempt to discover the problem and the cause of the issue.

Hoovey689

iTrader: (16)

Seeing as your RX is already 'broken-in', a few other variables may be at play. I see you live in Illinois, probably cold there right now. Check your tire pressure and make sure that's in spec. During winter poorer (and thus cheaper) quality gasoline or 'Winter' gas is used which can contribute to poor mileage. On your 2011 make sure you are using Premium 91+ Octane. Modern cars are smart enough to adjust for knocking and pinging should you use a lower octane, however you will lose a few ponies and another 1-2 mpg. Driving habits like hard acceleration, constant braking can also cause this. Lots of variable to consider. The easiest one though and I suggest, reset the AVG computer on the LCD between the Speedometer and Tachometer. Use the up/down on the steering wheel to find AVG then press and hold the 'Enter' to reset it. Odds are it hasn't been reset in a long time and thus the accumulation of miles does not reflect average fuel economy as close as it should.

airgas1998

better yet hand calc it...to make sure your within what your observing.

jollick

I agree with Airgas, also, fill the tank, drive it until at least below 1/4 full, refill it to one click after the auto shut off then manually calculate the MPG, do this at least twice to get your real MPG. I have found the Lexus calculation off by 1 to 2 MPG, showing more than manually calculated. But, always do the calculation from one full tank to the other.

julieu22

Thank you to everyone who has written in order to help me. I appreciate it. I am currently hand calculating my gas as two people suggested. With a little less than one quarter of a tank left, I have 233 miles so far, so pretty bleak, imo. I will say that we've had a nice warm up here in Illinois and for the first time I am reading 15mpg on the cars computer for mpg. For the record, I do not gun the car at starts but I do a lot of stop and go driving; with the possibility of hitting about 9 signal lights and 4 stop signs on the way to/from work each day. Oh, and I'm also not letting the car warm up any longer since the temps are warmer. For the month of Dec/Jan/Feb and utilized the remote start before leaving work which let the car run for 4 minutes before timing out.
I'll also reset the computer as one poster suggessted. Thank you again-Julie

jollick

Warming the car up for 4 minutes will not help your MPG, the engine is running rich to warm up and you are getting 0 MPG. Most manufacturers of modern cars do not recommend warning up a vehicle and some states prohibit it due to pollution. Older vehicles with carburetors needed to warm up a bit but fuel injected cars do not. Just IMHO.

Poqman

I would suggest two items for consideration. 1) Get a can of MAF cleaner and clean the MAF (mass air flow) sensor along with making sure the air filter is new and 2) disconnect the battery for 30 minutes. This should reset the ECU "learned" settings and allow you to re-teach the ECU based on your driving habits. Don't forget that the windows, door locks and moon roof has to be reset after disconnecting the battery. These are easy items to do for a garage mechanic.

FSportIS

iTrader: (13)

Yep, and my IS250 2012 consistently showing 2 to 2.5 MPG more than my manual calculations for 3 years! Therefore, to estimate my actual MPG, I tend to subtract what I see on the dash by 2.5.

On my IS250 2012, driving in 40% freeway, 60% local all 100% in traffic, I'm getting 23.5 from the dash board but actual MPG is 21 MPG.

My IS350 2006 however is CONSISTENTLY ACCURATE in the reading, I'm getting 18-19 MPG in both dash board and actual.

I think Lexus change their algorithm on the dash board to show you more MPG in the newer model or something???

julieu22

Hello-The last time I filled up, I reset the AVG on the computer per Hoovey's suggestion and this has increased the mpg to about 16 to 16.5 mpg's. Although it's funny w/the last commentator's thought of the computer giving an extra 2 mpg than what the car is actually getting because I ran the car as close to empty as I could (range on computer was 2 miles) and filled up. Calculating mpg by hand gave me 14.73 mpg's. BLECK! I am on my 2nd tank so I can run the numbers again.
I don't know if the computer was really off or if I am perhaps getting more MPG because of the warmer temps/not having to let the car warm up.
I have the remote start and used it during the frigid temps of below 0-15 degrees after it has sat outside while I'm at work. Even after 4 minutes of running, I will get in the car and the needle was barely at the "C" temp wise.
I find it comical that the Lexus employee didn't suggest the computer reset, but didn't find it unusual for the "cars are tested by the government" statement. I'd love to see how other RX drivers are getting 19-23 mpg!!!!

FSportIS

iTrader: (13)

I'll be jealous of RX getting 19-23 MPG lol. My small sedan IS is getting 18-21 all year long.

Don't trust the computer calculation because most of the time it is 1-2 MPG higher than you actually get.

Marqevans

I have had numerous RX's in the suburbs of Chicago. I always seem to be able to get at least 300 miles out of a tank of gas. More in the summer of course. That being said I don't have as many stops as you in my daily commute. Perhaps you should consider a hybrid in the future as those are really meant for stop and go driving.