cflutist

So we drive to our local Best Buy (to buy Gravity on Blu-Ray), hubby Websailor pushes a button to reset the mileage thingy (very technical here ... lol), then puts the car in SNOW MODE so we can use both electric motors on dry payment on a sunny day in CA. Average mpg went up to 31.3 mpg, with most driving at 40 mph (except 5 miles at 60 mph on a brief stretch of the freeway).

Well this is better than the 19+ mpg we were getting earlier, or was that in the 25+ mpg in ECO MODE. I don't really remember.

I say, let's just drive the thing. I'll let him elaborate more later.

p.s. My sister has a 2009 RX400h and kept telling me that her salesman told her that the car had 9 computers onboard. So I called Lexus today and asked about our RX450h AWD and was told that there are 30 computers onboard.

Aptosuser

That's terrific. I haven't seen anything like that kind of improvement from using snow mode in my local driving. I want to get better mileage on the 2-mile stretch between our house and our health club. I'm pretty sure that the reason snow mode hasn't improved it much is the fact that this stretch has a lot of ups and downs. I try to squeeze as much MPG out of the down segments as I can while doing whatever I can to keep the car on the battery as long as I can on the up segments.

By the way, what happened when you hit 60 mph on the freeway? Did snow mode turn off at that point?

Today I finally figured out how to get the RX into EV mode. (I went back to the manual and found -- as someone here may have mentioned before -- that it won't come on when the engine is still cold.) EV mode definitely perked up my MPG when I relied on it while pulling away from stop lights. But you've gotta keep a very light touch on the accelerator so as not to upset it so much that it turns off.

websailor

LOL, a bit of elaboration! Before we left today on a relatively normal shopping trip (city streets, several places to shop at), I did the mileage UPDATE because I wanted to see the MPG for this trip, not averaged with any previous trips. We traveled about 8 miles to our first stop (Best Buy) at which point the MPG was 31.3. To get there we went slightly up, then down our big hill, then along the city roads which have various slight uphills and downhills. As much as I could, I tried to not use the ICE, except when pulling out from the stoplights - California drivers here are quick to blast their horn at you! The top legal limit along the way was 40 mph, the rest 35 mph or less. We had one fairly good downhill along the way and probably had about 8-10 stoplights a few of which I coasted through on the yellow (or green).

I do believe the HYBRID SNOW mode helped our MPG on this segment.

Immediately after that we went on the freeway at 60 mph for about 5 miles. That is really slow around here, but I was in the right lane and then the turn lane and there were six other lanes, so everyone could get around me. However getting on the freeway, I had to accelerate quickly, so the ICE was used heavily. I noticed on this stretch the MPG dropped down to 29.8.

Disregard this. The 19+ mpg is from when we first picked up the car until we finally figured out that we should use the UPDATE function about 3 weeks later - so it was the very first miles on the car from before we bought it and through our first driving it. After reading this thread, I learned how to drive better, and that is the 25+ MPG - averaged over about the next 3 weeks, until today. BTW, the car probably only has about 300 miles on the odometer, so factor that in also. Plus I'm a newbie hybrid driver.....

LOL, I'd like to learn a bit more about our neat new car, so the "let's just drive it" is a bit off in the future.

Finally, after our last stop, we headed back home on the city streets with stoplights again. The MPG went back up from 29.8 to ~31, then we hit the big hill (230 ft elevation gain) to our house and it went down to 30.0 MPG. That's not bad!

I have to try the same or similar trip after resetting the MPG and just using ECO mode. I think it will be a bit lower simply because it is my impression during driving today that the ICE was not getting used quite as much as normal by a small amount.

I completely understand what Gotin is saying about the gas pedal - it is very subtle when trying to accelerate and keep it in all electric mode. I'm still trying to find the sweet spot. Just a tad too much and the ICE kicks it. But it sure is nice when I can get a good long stretch of all electric only distance in!

websailor

Okay the "thingy" remark by my DW is making me tell this side story, hope no one minds. Back in my younger wilder days, we drove a restored Jaguar XK150 - took a girlfriend out one time very late at night on the freeway with my friend driving. Not being familiar with cars, she asked what the gauges were:


My friend pointed a few out and then pointed to the tach and told her it was the speedometer and that she should watch it.....and soon took the XK150 up to 50 on the tach (just below redline), cough, cough, um, speedometer. Pretty soon her eyes got really big....

The game was up when we encountered another car going about 65 mph and passed it like it was standing still. At that point she started screaming nasty stuff at us. I don't think she ever figured out which gauge was really the speedometer.

Aptosuser

Websailor, were you still in hybrid snow mode when you drove on the freeway at 60 mph? If so, what happened? Did the car drop out of snow mode at higher speeds? Did it resume snow mode after you got off the freeway?

websailor

I'll take it back a step from the freeway first.

So at Best Buy, I turned off the car to go shopping - it was in Snow mode up till then. By turning the car off, it reverts back to just ECO mode.

So upon starting the car up, I had to put it into Snow mode again, using the buttons on the steering wheel. I headed out, and got to the freeway on ramp. Acceleration seemed fairly normal & robust - because I needed power, the ICE came on. I didn't see at what speed the rear electric motor went off, but it did sometime while getting up to speed. (I had to merge over 3 lanes and some nuts were going very fast coming up, making it difficult to merge, so that took all my attention).

On the freeway, the dash showed the normal green ECO mode light and the amber SNOW HYBRID lights. The power display showed the ICE and front electric motor getting power. No power to the rear electric motor. So, as I expected, it operates in FWD at the higher speeds.

I'm guessing the computer only allows the rear electric motor to be engaged at lower speeds - maybe below 35 mph?

Upon exiting the freeway and doing the wonderful coasting, the ICE went off and both motors pumped energy back into the batteries. At the first stop sign, everything operated as before on the first part of the trip.

I never took it out of SNOW mode and neither did the computer. I could see the amber light from Best Buy all the way to Starbucks (the next stop) even with the short freeway section in between. The only difference I noted was the actual operation of the motors, engine, and battery.

I'd say the exact same thing (the actual operation of the motors, engine, and battery) if you asked me about the ECO mode between point A and point B.

So far I'm encouraged about this, but I need to do a similar check with just the ECO mode to compare. This whole trip was probably about 20-25 miles, so it was a bit farther than we usually go.

It's going to take us forever to break the car in!

Aptosuser

I know all about crazy Bay Area drivers, especially on the Nimitz in the East Bay and 101 on the Peninsula.

bring

pardon my ignorance, but what is ICE?

Cruiter

On the Lexus/Toyota Hybrids, it's the acronym for "Internal Combustion Engine" as opposed to the electric motors.

oohpapi44

iTrader: (1)

Will also stand for "In Car Entertainment" in the modding sections.

cflutist

So in SNOW MODE, I noticed that both front and rear electric motors are running essentially providing the AWD.

Does this imply that the RX450h FWD does not have a snow mode then? If it does, does anyone know how SNOW MODE works on a FWD?

(There were 5 hybrids (white, white, black, silver, gray) on the lot the day we bought our car - 1 FWD and 4 AWD. I would have preferred the silver color as opposed to our N-Gray, but it was FWD and we figured that if we were spending this much on a car, we should get an AWD one).

bring

fyi - i was watching the energy screen while in snow mode yeserday and the rear motor was not engaged. so it is not an override to the "wheel slippage" system of transfering power to the rear axle.

oohpapi44

iTrader: (1)

The manual makes no mention of AWD vs FWD when it comes to snow mode so the implication is that it does exist. I've never heard anything about snow mode affecting how many axles are engaged. In my GS, the gearing is changed to avoid you spinning out and give you more traction. In short, it retards the vehicles performance by limiting the switching of gears. Believe it would be the same for the RX as I've yet to see anything state othewise.

Aptosuser

And not to be confused with Immigration and Customs Enforcement.

gotin

You are absolutely right.
GS is starting in second gear when Snow Mode is engaged.
HYBRID SNOW Mode: When activated, this mode helps enhance control stability due to accelerator pedal operation. This mode moderates the amount of system power output in relation to the amount of accelerator operation. On AWD models, if the front wheels slip, the assist power of the rear electric motor is optimized, enhancing start-off stability.

I would say: The assist power of the rear electric motor is optimized in order to prevent the front wheels to spin, thus enhancing start-off stability.