So far we've been averaging 26-28+ mpg depending if A/C is used in one month of driving, which seems really good but i don't think our 2006 400h is working properly. the owners manual says you can expect to go 15-20 mph on battery power only, our engine start about 10 seconds after we start car no matter what, even in park. it doesn't seem to me that we ever run just on battery unless at cruising speed on flat road. not even in reverse.

i tried doing the ISC reset myself but couldn't get arrows to go from wheels to battery on display. i took to lexus dealership and they said they did it and i have Data sheet from them that says ISC Learning - Compl

on the dash display, the battery level never goes above the +/- indicators no matter what. in fact when i left lexus dealership it was almost empty then charged back up to the +/- level.

since i'm getting 26-28 mpg already it's not the worst thing compared to others but if it's not running right and i can get better that why not.

my questions are what levels are other peoples batteries at? we've got 80k miles on 2006.

and if things don't seem normal should i be trying to have this fixed under warranty? at minimum i've got 2yrs and 20k miles and hybrid system. what do i tell them problem is?

has anyone else had this problem?

thanks!

 

It sounds like you RX400 is acting the same way mine does (2008 with 51k). I think the engine always runs a while on start up to warm up the engine. It's pretty rare that I'm able to cruise on electric power only. It has to be a pretty flat road and generally under 25 mph.

My car has been getting between 26 and 28 mpg according to the trip computer, but my actual calculated mileage is a bit lower in the 25-26 range.

Jeff
2008 RX400h

 

If your hybrid system wouldn't work you wouldn't be able to get mileage like this - this is a well over 4000lb truck - usual mpg is in low 20s - if you baby it

 

Mine (2008 RX400h) acts in a pretty similar manner--I'll start it, and it will move on battery power alone if I shift into D soon enough, but either way it will always insist on starting the ICE within 10 seconds. The ICE usually does not run nearly long enough to achieve anything like what I would call "operating temperature" though--we're looking at perhaps a minute or so of ICE operation at the most, unless the battery was already very low upon start.

I have no idea why Lexus apparently designed it this way; it would have been super-cool if the ICE could just remain off at "Start" unless it was actually required to charge the battery. Having it run for a minute sounds like perhaps they just want to ensure that it WILL start when required.

 

The engine turns on in about 10 seconds after you start the car is to warm up the engine. That is why you will notice when the vehicle has been driven earlier and you try to start again, the engine will turn on and then off right away because it is already warmed up. This is to make the engine run more efficiently, which in term gives you better mileage. My cousin has a HS250h and we try to use the EV button to prevent engine from turning on, but the car will disable the EV function and start the engine after about 10 seconds.

Also, there is a way to keep the RXHybrid in electric mode as long as you can by looking at the power meter. You will notice towards the bottom left there are the thick blue dash lines. Try to keep the needle in that area below the solid white line. You can drive up to 42-43mph before the engine will start (hybrid design; gears related). Keep it in the blue area will let your car drive in the electric mode even on the freeway. Of course, this is only if you just want to cruise.

 

Seem to be very normal. my battery always states at 60~80% charged and my avg is 23MPG. There is one week I make it to 28MPG but I drive like turtle....... I'm happy with 23MPG for NYC driving vs 16MPG for my friend's RX330