05RX330AWD

05 RX330 AWD, 138,000 Miles......
Spark Plugs were changed 10,000 miles ago with one Ignition Coil & one Fuel Injector (which ones unknown) by the
previous owner, no idea if the outfit who serviced is reputable or not. Engine Oil was also changed by previous owner,
unknown for what brand or grade on the sticker.
I changed the Air Filter, Differential Oil was replaced due to a leak, Air Pressure for Tires is fine, Transmission shifts fine
but could use a oil change.
Filling up with Octane 91, easy & smooth on the pedal, & No Codes....yet at the end of the day I would think I am driving a
Corvette.
I'm thinking possibly doing a reset, disconnect negative on battery for 30 mins to allow the RX to relearn, although hesitant
since this is the only issue for performance
Also unsure if the Trip Info for MPG on the Nav. is accurate or not or still using some info from the previous owner.
Also, as I read in many posts on CL, winter (still around 30 Degrees F here) has some effect & true, short trips effect millage.
Previously in comparison a 05 Equinox AWD with unknown when the Spark Plugs were changed (but looked fine) & only a
Air Filter change, I was averaging 20 MPG City with no need for excuses.
Any ideas

tbm5690

Do you start it and let it idle to warm up with the winter temps? If so, extended idling definitely effects things. I let the autostart warm things up every winter morning for a minimum of 10 minutes in my '05 and city driving in the winter I get about 13-14 mpg. That city driving does include some stretches of consistent 40--45 mph speeds though...if you have a lot of stop-and-go situations, those numbers would make sense. Also, is this actual calculations based on gas at the pump or are you using the numbers the trip computer is spitting out?

05RX330AWD

According to your location I would assume our winters would be similar, although here on this Island, nothing is distant, from one end of town to the other in any direction is less than 10 mins away & there is no way 45 Miles an hour is possible until you leave town....
therefore yes, stop & go in 5 minutes is a routine drive.
Lexus recommends not idling more than 20 mins in the manual therefore I usually idle for between 5- 10 mins. The calculations are from the Trip Info for MPG on the Nav & also from a Dashcommand app with a iPod which matched up.
I will try a manual calculation in the near future, still, a 05 AWD Equinox 3.4L with no pampering & the same drive conditions gets double the gas millage compared to a RX is baffling.
Then again, the quality in the ride & features favors the RX way more than double. Possibly 18" alloy rims & winter tires compared to Equinox 16" also reduce the gas millage some.

RedGemini

The idling really seems to kill economy for the 3.3L. I stopped letting mine warm up after the first tank of gas, unless the temps were below 10º F. Even then, I only did it because the power steering let me know it's too cold... LOL.

Another thing to consider - comparing the GM 3.4L to the Toyota 3.3L is truly an apples to bananas approach. The 3.4L wasn't blessed with power in comparison, but it was a very frugal pushrod engine. My dad's former '01 Monte Carlo regularly saw over 30 MPG, and he didn't baby it. The RX is also much heavier, which doesn't help at all.

In the end, that still seems low, but we're still getting fed winter blend gas for a little bit longer. I'm hoping summer blend really helps. My '12 Hyundai Sonata SE 2.4L was terrible on winter blend. I saw mileage dip to the teens, especially if I let it warm up for any length of time.

05RX330AWD

Agreed, the RX does have more pep than the Equinox, although I found that to be much more true with the 91 Octane, in the Equinox I would pump the cheapest gas I could find. When I first drove the RX which most likely had cheap fuel from the previous owner, there was less a difference compared to the Equinox.The weight factor is something I overlooked, 05 AWD Equinox 3776 lbs vs the 05 AWD RX330 5245 lbs., almost 40% heavier than the Equinox...then all certainly makes more sense
But how do some of the CL Members who claim they get 19 MPG City get there

RX3302004

My RX computer says 20.4mpg or so when I check it. Almost all city with air conditioner on. Nothing special about the vehicle, not add-ons, just regular fuel.

mdbrown

Mine tends to stay in the 18.6 - 18.9 range with a reasonable mix, mostly city driving.

05RX330AWD

I suppose the only thing I could brag about is that I do not even need to turn on the Air Conditioning too stay nice and cool if I drive in reverse since it's 29 Degrees F here.....
the photo explains it all.
Anyone done a reset of the ECU for better gas millage? Never had such a gas millage issue before as this one.

numbafree

I would post my city MPG but my RX is about 70lbs lighter, and I do drive like I stole it. but I usually drive 90% hwy (commute).

05RX330AWD

I drive the RX like an old fart (wait.. I am an old fart) which doesn't change a thing, warmer today, slightly above freezing & down to 9.6 MPG. .....
& I am slightly lighter without the Tailgate Glass.
Still waiting to hear from CL members from experience if a complete reset could help.

BlackLexRX

Go for the reset. Don't know if it will improve mpg, but it won't hurt anything. You'll just need to reinitialize your windows, settings, etc. Def worth a try to improve your mpg.

05RX330AWD

As a retired person on fixed income & Premium fuel prices @ $4.50 a gallon, hopefully it will help some.
Although in summer I am more active as a Professional Panoramic Format Landscape Photographer (Self Publisher) & do much more millage, that is when the fuel millage is much more of a concern.
Prince Edward Island is a really tiny island, yet traveled more or less close to 2,000 miles on the island to complete my project.
http://www.panoramicpei.ca/
My goal is to try to overcome all the repairs & maintenance issues by summer as I will move on to start photographing Quebec. The millage will triple easily by then.
Thanks,I will give that a try & post results eventually.

pablo87

im the original owner of a 2005 Rx 275k km. from my experience, most important by far is to clean the maf and throttle body. ideally the tb is removed ( i didnt, beyond my capability), otherwise take your time with proper cleaner, use q tip if you have to, be careful it is electronic ( ie have someone fully depress pedal, watch your fingers as butterfly could open or close on its own).
same for maf, use proper cleaner, make sure dirt is not "caked" on. Careful, this is an electronic part essentially.
In both cases, there is an assumption that just spraying a bit will work but it doesn't always. Cleaning must be thorough.
One symptom these are not clean is instantaneous mpg jumps around even though pedal pressure is not changed. After proper cleaning, the fluctuation should be less.

PCV should also be changed but not sure if any effect on mpg. Use Toyota/Lexus original.

The above is my experience.
good luck.

05RX330AWD

Really was hesitate for MAF clean realizing the sensitive nature of the part from what I read.
I haven't noticed the MPG jump with a constant pedal pressure, then again, didn't closely look for that.
I'll pay closer attention, thanks for the tip.
As an example, the MPG does jump to 30 MPG + as I release the gas pedal to coast to a stop therefore certain functions seem normal.
The final math calculation for MPG is disappointing.

RedGemini

If I have the time today, I want to clean the MAF sensor and do a SeaFoam Spray treatment to the intake. I'm sure neither of them have ever been touched.

As for cleaning the MAF, it's pretty simple. Get a can of MAF cleaner. Gently spray it thoroughly. Allow it to air dry (dries pretty quick). Reinstall. You should be able to see if it's clean after the first couple sprays. If it still looks a little dirty, give it a couple more sprays.