Newbie here - Cold weather is a FE killer for sure. My FE rocketed last spring (from 22 to 26-28) once the warm weather hit AND my 08 THH logged its first 4,000 miles. But I am now driving it for max FE (I think?). My best tank has been 29.7.

The info on green hybrid has been a tremendous help.

I do have two questions - 1. does anyone know of a published book or guide for us Hybrid owners in order to learn all of the tips and tricks for max. FE? and 2. does everyone agree with the ceramic heater for the cabin? I thought the goal was to get the battery and engine up to adequate warmth, as well as the cabin (secondarily).

thanks to all!

 

"..I thought the goal was..."

The manufacturer's "goal", design goal, is to get the catalyst heated up to operational temperature as quickly as possible within reason. Pre-heating the engine coolant may, and i say "may", fool the engine/transaxle ECU firmware into thinking the catalyst has been raised to operational temperture before it actually reaches the target temperature range.

My '95 LS400 has 225,000 miles at the moment and is throwing a code 0430, bank 2 low catalyst efficiency. I doubt it would have lasted this long with a coolant heater.

My statement is not intented to cover areas, say in MT and AK, wherein engine coolant heaters are the norm in the wintertime.

 

Try switching the oxygen sensors, and see if the error moves to the other bank. O2 sensors are cheap, they fail farily often, especially with older vehicles that are passing more goo along the pipe.

MM

 

By the way, the cats light off pretty quickly. They tend to be ready before the oxygen sensors which live right in the exhaust stream. That's why a lot of oxygen sensors are three wire and heated.

MM

 

At 225,000 miles I suspect the catalyst but in any case I have first replaced the #2 oxygen sensor on that side and swapped the two #1 oxygen sensors R/L. Also new spark plugs. All of the oxygen sensors are 4 wire but only the front heaters are powered.

Testing continues....