carbon

I have 2006 RX400h with over 93k miles on it. I remember when I first purchased, it used to get 27 - 29 mpg. But now it only gets 23-24 mpg. (Not to mention that my driving habit never changed..) It seems #mpg goes down as the hybrid battery gets older.
Does anybody who owns 400h have same experience ?

rcy

Have you ever replaced the 12 volt battery under the hood? Or had it run down so it needed a boost?

If you have, you may need to do the ISC learning procedure. Look here...

http://us.lexusownersclub.com/forums...howtopic=58929


If you're not comfortable doing it yourself, take the TSB to the dealer and ask them to check to see if the ISC learning procedure is complete (they can hook it up to their computer to confirm this)



If you are comfortable doing it yourself (I have done it many times) see here

http://us.lexusownersclub.com/forums...howtopic=58930


Don't forget as well if you live in a cold climate, that winter gas will negatively affect your mileage, as will driving in the colder weather - the ICE must run more often to provide cabin heat and keep the cats at proper operating temperature.

lexus114

Man,I`m only getting 17.1 MPG w/Premium on this winter time crap!

rcy

My mileage went for a dump in the cold weather as well. From about 8.2 l/100km to 10 l/100km. Bah....should move to Dubai or something...

tod071

I used to get 29mpg when I first bought mine. 27 now. But I've also modded my RX since 2006, including a few boxes of Dynamat, so I'm still happy.

carbon

rcy,

Thanks for a valuable info. I have tried by my own and it worked. Now I am getting 15% better mpg. Yes, I did replaced 12v battery because it died. The battery was only 3 years old and I think it is supposed to last much longer than that. But anyway I am happy now for the better mpg.

rcy

According to the TSB, this only applies to the 2006 models...Dunno if it is needed on the 07 and 08 or not. When I did this to my 2006 400h, the mileage went from about 10 l/100km to 8 l/100km.