Hi,
I have a question on boosting MPG or best driving habit to get the best MPG possible.

What speed would you recommend to drive on highway ? 65/70/75 ? to get the best MPG on highways?

Air pressure ? do i have to wait for pressure monitoring device to alert or i should check tire pressure proactively once in a while ?

Fuel - 91 octane is best for best MPG or any other suggestions ?

Also i tried the power outlet below one(close to front passenger / driver's feet) - is there any switch to get it on/off ? it looks like no power for me in this outlet.

 

1) I feel that once you are above 65mph, the mpg goes down.
2) Turning on heater in Winter will dramatically reduce MPG in my case.
3) Check tire pressure once a week is the best practice. Keep it inflated between 30-32psi when tire is cold.
4) As for gas, for best MPG, use 91/92 octane without Ethanol
5) When driving at highway speed, don't open the windows for saving air conditioning which actually cause worse MPG.
6) Don't start/stop suddenly, make amooth move

There doesn't seem to have a switch. But the fuse could be broken if you don;t get the power.

 

Welcome to Club Lexus, rksingh.

The slower you drive the better your MPG. Though, going too slow can put you at odds with other drivers on the road. Stick to the speed limit and you should be fine.

Best to be proactive about your tire pressures. Pick a day, say the first Saturday of the month, add it to your calendar and make it a habit. Purchase a quality pressure gauge and be sure to check it against what values a shop is getting with theirs for comparison. The tire pressure sensors, such as the one in your 2004, are meant to look for one tire much lower in pressure than the others. If all tires drop 10 psi, for example, the monitor will think everything is still fine.

If your RX is happy with 91 octane then stick with it. You can try running a few tanks of 87 or 89, one tank is not enough for a statistical comparison, to see how it affects your MPG. Lower or higher octane fuel "can" have an impact on MPG, however, it depends on a lot of factors. In the Owner's Manual it states that you can run 87 octane, but that 91 is preferred. Personally, for day-to-day driving I use 87 octane and when traveling to PA with the vehicle fully loaded I will run a higher octane of 89 or 93.

As for the outlet, you either have a blown fuse or it has gone bad. Check your Owner's Manual regarding fuses to see which one controls that location and check to see if that fuse is good or bad.

 

Of course 91 gives you a (slightly) best MPG.
The point is, is MPG you're really interested in, or MP$?
If the latter, 87 is what you really want.

 

I would agree with all above....you don't drive a racecar....so keep the foot out of the right pedal and keep track of your tire pressure.

 

I have observed with my current RX as well as my 2001 RX300 that they are very finicky as to how you drive them. I.E if you have a heavier foot, dont expect too much in the mpg department. It`s a pretty heavy vehicle for the size motor we have.

 

I save a lot of fuel by being observant of what is ahead. I don't tailgate and I watch for upcoming light signals. When it turns yellow or red take you foot off the gas and coast as much as possible without going to ridiculous extremes and being aware of other drivers. Accelerate smoothly. Driving with cruse control enabled where possible makes for better economy. I keep my tires at 32 psi cold and check them regularly. My RX330 makes noticeably better freeway mileage on premium fuel, but not much difference in city driving MPG. I do about 85-90% highway driving. Over the 9+ year life of my RX330 I've averaged 23 MPG measured. On long 1500 mile freeway trips (23 of them) at a steady 75 MPH, I range around 25-27 MPG.

I also can buy pure (ethanol free) gas where I live. You might also be able to find pure gas by checking this link: http://pure-gas.org

Adding up what I've experienced in my RX330, pure gas can yield 1.5 - 2 MPG more than e10 fuel in both city and highway driving, 91 vs 87 on the freeway can yield 1.5-2 MPG more than regular.

 

It's not just a matter of speed. You want to use the least amount of throttle pressure needed to maintain whatever speed you're cruising at. The harder you accelerate the faster you'll consume fuel. Conditions such as incline of the highway, traffic, etc also play into fuel economy. You want to minimize acceleration and deceleration. Pay attention to what's ahead and anticipate and adjust ahead of time. You can't just expect a specific speed to provide drastic improvements in fuel economy by itself.

There are plenty of resources out there if you want to read up on driving habits to improve fuel economy.

Don't rely on TPMS. Regularly check tire pressures.

 

From my experience driving in mostly suburban traffic and slow n' go traffic congestion, I find that accelerating as quickly as possible before the ICE turns on is optimal. If there are cars behind me, I'll accelerate quickly (kW in the 50-100 range), then once I hit the speed limit or if I'm accelerating faster than the car in front of me I will release the throttle, then reapply so I'm gliding on electric power only. If the light ahead of me is red and I'm not in anyone's way, I'll coast/lightly brake to recharge the electric battery. For the freeway, I'll accelerate up to 73mph before I do the pulse and glide and I'll try to engage the synergy drive (both electric and ICE). By little holding the throttle, I'll achieve 30-99mpg for about 25 seconds while slowly decelerating. When I hit 63mph or I'm going too slow for the car behind me, I'll accelerate back up to 73mph and do it all over again. By doing this, I get an average of 35mpg in the city and 28 on the freeway.

As for tire pressure, I try to keep it around 35f/32r. I recently let it drop to 29f/27r and the car had a lot more roll resistance. I could not believe how different the car felt after pumping the air back up.

I use 87 octane during the fall-spring, then 89 during the summer.

 

For MPG, I always turn on the cruise control and keep it between 60-65 during highway driving.

As for octane, I always use 87 since it does not require premium gas. I was just thinking about this on my drive into work today if I am using the wrong octane since I hear the engine ticking every time I shut off the car.

I might try 93 octane (avail in NYC) and see if that improves my MPG.

 

I have an 08. I get 25 mpg. I always fill 91 octane. Tire pressure at 40. Drive on the hwy at 72 mph. With ac, I get 23. Always smooth acceleration and mostly highway. Ymmv.

 

Wow, tire pressure at 40, doesn't that equal a hard bumpy ride? The Lexus recommended TP is 30 and most CL members run at 32.

 

You might be surprised at how well higher tire pressure rides at highway speeds. I always over inflate my tires when I take my cross country trips and they ride really well. Of course I am carrying a heavier luggage load too. Typically when I start out I inflate to 34PSI at about 10 degrees F and head south. By the time I hit Georgia it is in the 70's and the tire pressure has risen to 40 PSI. I usually deflate the tires a bit in GA and when I get into FL it is up another pound or two. Funny thing is that on the freeway, 40 PSI feels the same as 32PSI as far as ride goes.

 

My tires have a max pressure of 50 or 55 psi. So filling 35 or 40 doesn't really affect the ride much.

 

Data Pt;

2004 RX-330 AWD, with Sears X-Cargo carrier on top going West on I-80 8/25/13, ~77*F. Last computer readout to my drive from 89 octane fill in PA was 67 mph avg with 23.3 mpg with A/C for ~70 miles (includes 1.5 mi local road). It might just be my conceit, but the mpg bar graph on a flat, non-windy road with cruise -and- warm temps shows some bouncing around that I guessed -might- be knock sensor pulling back timing. 89 octane give a much steadier readout and better (and with $0.10/gal increment over 87) economics by my reckoning. I'm also believer in cruise control to maximize mpg. Relatively new Goodyear FuelMax tires inflated to 33 psi. Rolling resistance is not linear, there are diminishing returns IMO. Lastly Mobil 1, 0W-30.

YMMV.