All,

First, let me say that I love my 2008 Toyota HH. So, I'm not "complaining" so much as just curious as to whether what we have seen is an issue or just par for the course.

We live in an urban neighborhood that should be pretty ideally suited for the HH. Most driving is in the city, with about 10-20% on the highway around town. Our avg mileage is probably around 25.

The issue is that our hybrid performance seems inconsistent. We can almost never get EV mode to work even if the battery shows all green. Once in a blue moon it will come on, but even if it is warm outside, battery is all green, driving slowly through our neighborhood, EV mode rarely comes on. Always says "not available".

That being said, I know that EV mode is not always the best choice. Which leads me to the rest of the story. It is very common for our vehicle to show "poor" gas mileage (<20-30mpg) on the lcd display for the first 10-20 minutes the car is on (even happens in moderate weather, just gets much worse when it is cold). We could be coasting down a hill, driving 15mph down our street with the foot off the pedal with all showing good (power back to the battery or all EV). Now, eventually it normally "warms up" (for lack of a better term) and we get to the point where those same situations peg the mileage meter at 60. But the car seems to be VERY slow out of the gate in terms of mileage.

Any ideas? Is the traction battery really that slow to warm up?

Would a block heater help?

Anyone? Bueller? Bueller?

Thanks.

 

I have a 2010 Highlander Hybrid, and have expereienced basically the same thing.

For the EV mode, I get it to work pretty well when it's warm out. I don't use the EV button much, but more often stay in EV as long as I can when the vehicle decides to enter it. The biggest detraction I have found is when running the environmental systems. If you are running the heater or A/C, then EV comes on way less often.

For the slow mileage at the start, I think this is common of any car until the pieces all start moving easier. I think of it this way: If I'm getting up from sleeping all night, I move slowly for the first few minutes too. But once I get going, I'm at normal operations conditions

 

I guess if it was consistent with temperature I could explain it more easily However, our issues appears to be more likely to happen when it is cold and the battery is not above 3 bars, but does happen somewhat frequently even when those conditions are not present (i.e. reasonably warm but not hot and nearly fully charged battery).

Is there some other "warm up" condition that I am not aware of?

 

I am not sure how different the 2008 is from the 2006 in terms of the programming that enables “EV” mode. The 2006 does not have an EV button.

That being said, on my 2006 Highlander, the vehicle will not allow you to drive under full EV mode (modest battery-only power with the engine off) until a few conditions are met. The engine coolant must be warmed up to at least 164 degrees F. (Fully warmed up is about 180 degrees F). This can take several minutes of driving, dependant on outside temperature.

Once you hit 164 degrees, the vehicle must experience a full stop longer than 10 seconds with the engine running. Once the vehicle is stopped, the engine will continue to run for about 10 seconds and stop on its own. Once the engine stops under this condition, you are set for full EV mode operation. Note that this condition is not always readily completed on your drive which will delay when and even if full EV capabilities are enabled. I have a Scan Gauge II in my Highlander so I can monitor the actual coolant temperature. However, just watching the dash temp gauge should give you an idea when the coolant is warm.

I’m often surprised how few stoplights allow me to stop for the full 10 seconds before the light turns green. If you begin moving again before the engine stops - no dice.

Sometimes I reach the required 164 degrees but if I am driving at the time over 40 mph, the engine will automatically stop while I am coasting to a stop. This type of stop with the engine off while coasting down in speed will not set the full EV mode capability.

I learned a simple trick to ensure getting EV mode enabled after the coolant is warmed up. If you come to a stop with the engine already shut down, hold one foot on the brake so the vehicle does not move. Then press your other foot on the accelerator just long enough to restart the engine and then take your foot off the accelerator. The engine will run for 10 seconds and then shut off. You now have access to the full EV mode assuming your engine coolant is warmed up. If the engine stops immediately rather than running for 10 seconds when you do this, it means you are already enabled for full EV mode.

I don’t know why Toyota requires this 10-second-engine run-and-then-stop-while-stopped condition to allow full EV mode.

My drive takes me down 2 miles of surface streets and then on to an expressway for 9 miles. In one bad snowstorm, I got on the expressway before the engine had warmed up and was stuck in traffic going a continuous but excruciatingly slow 3-10 mph for over 1 hour over that 9 mile stretch. I never got a chance to stop for the required 10 seconds due to the flow of traffic I was stuck in. Due to this, the vehicle refused to go into EV mode for the entire hour of driving at this slow speed! My mileage was horrible at less than 10 mpg. Had I been able to enable EV mode before getting on that expressway, my mileage would have been over 30 mpg for that slow extended crawl.

 

Hi,

We have an '09 Camry Hybrid, and picked up an '09 HiHy at the end of the summer. I have been driving the Camry for over a year, and one of the tricks I learned (which has probably been mentioned a zillion times by now) is to speed up (gradually) to about 55-60 km/hr (so almost 40 mph), quickly let off the accelerator for a second or shorter, and then lightly, lightly (egg shell) depress the accelerator again. When the ICE comes back on, let your foot off again quickly and then depress lightly again - so long as you have close to 1/2 a battery, and the temperature conditions are ample, you will find yourself in EV more often than not...

With speed and a bit of momentum, the HiHy performs much like the Camry...Sure, it's heavier, and hilly areas, driving into the wind, etc. will affect how much EV time you can milk out of the battery...I find trying to get into EV off the line much more difficult in the HiHy because of the weight difference and how slow it seems...

I think the EV button is a bit of crock, and I can get into EV with the method above when it's warm enough outside, and the engine (coolant) has also had time to warm up...Give it a try...We average about 7.8-9.5 L/100km (25-34mpg) in the HiHy, even this winter up here in snowy, cold Alberta...Well, there's a chinook blowing through now, so it's warm and mileage goes up too...

 

I always drive my 2008 HiHy with the econ mode ON. After it warms up, it will almost always go into the EV mode after waiting at a stop (unless battery is real low). When the road is level or very slightly downhill I can usually keep the engine off for a mile or two at 30-35MPH as long as I stay below 1.75 bars on the power meter

I use a ScanGauge to monitor RPM, making it much easier to determine if engine is running. Also I have discovered that above 42MPH the engine is always turning, even when coasting downhill. I think this is necessary to keep the CVT differential motor from spinning too fast.

The EV button is somewhat unpredictable, but will usually engage when at a stop. The EV mode always disengages at 25MPH.

The last 200 yards into my garage is about a 30 foot rise. With the EV button engaged, I can make this climb with the engine off. If I don't push the EV button, there is not enough torque available and the engine always starts.

My wish for the EV system would be that the car would go up to 35MPH before the EV mode disengages.

 

Ok, I'm back with more odd behavior. Up until it got very cold we were getting 24-27mpg on average. Our driving behavior has not changed. However, when it got cold (below freezing) our mileage dropped to less than 20mpg. This just does not sit with me.

Here are a few examples:

First, last night I drove the 08 HH on a drive that was part expressway and part city driving. It would not get above 30-40mpg on the readout screen (not tank average, but rather the live reading/average). The engine temp was almost at half (maybe 5-10 mins of driving), and I was literally coasting down a hill without touching the accelerator and it would not get above that value (battery was around 4 to 5 bars according to read out). This eventually improved but it took about 20 to 30 minutes. Now, why should that be the case when it is 36F? I was driving it lightly, only two people in the car, battery showed as being pretty near fully charged, and still had this trouble. I even stopped for a full 10+ seconds once as a previous poster noted. Our latest tankfull has us at 16.5mpg.

When its above 45 or 50F we have few problems and get about 26mpg. Once it gets anywhere near freezing the gas mileage falls through the floor.

I pay attention and try to do everything I can to maximize mileage short of car modifications or an engine block heater. This severe sensitivity to temperature seems out of hand to me. Its not like we live in Alaska (we live in Louisville, KY).

I guess I'm left wondering if this is jut the way it is or if there is something wrong with our car.

 

The NiMh batteries are limited by chemistry. Lithium even more so. Even a fully charged cold battery below 45 F will have battery controller imposed power limits. The limits widen as the battery warms up. NiMh battery warm up and cool down can be very slow processes. When a fully warm battery is parked, it may take up to 18 hours to cool to the outside temperature. Upon next morning restart it may be an hour before it warms up enough to be fully utilized. The engine however is hot enough in about 7 minutes. So the hybrid has a battery that is charged but too cold to help.

Long park times in cold followed by short trips (less than 20 miles) hurt FE. It is just physics and chemistry.

 

Thanks for the response. I guess I understand that but a 30-40% drop in mileage seems extreme. Is there nothing I can do to help? Once again, if I lived in Alaska I would understand....but I live in KY. Yes, it gets pretty darned cold here at night (HH sits outside), but not like Minnesota.

Sounds like even a block heater would have limited effect. Is there any way to warm up the battery short of an attached garage (which is not in our plans at the moment)?

 

I know it sucks but battery chemistry has a knee that is unforgiving below 45F. Then requirements for in-cabin heat and defrost kick in around there as well. Add the cold tire resistance and extra final drive cold losses and anything below 50F costs more at the pump. I see a solid 10% loss on my 2 Mode system based on a 1 hour commute to work every day. My 2 week break at Christmas I set a new record low of 16.5 instead of my "normal" 19.5 winter mpg. Short trips all engine powered. A solid 25% loss form simmilar summer kid shuttle.

If you did the attached heated garage or some sort of heated battery and or hybrid drive... you just pay for coal fired energy down the road at the power plant.

The comming plug ins will have some sort of battery thermal control. At the cost of your electric bill. But they may be configurable to be warm in the morning just like a programmable coffee pot. Cabin, engine, and battery.