New 05 Corolla S With Low Mpg And Rough Idle - Corolland: the Toyota Corolla Forums

Guest 05corollaS!!

Hello all. Just curious. I recently (last week) bought a 05 Corolla S. I do alot of highway driving, and have 1300 on the odo already. The car seems to average about 27 mpg, and the engine seems to idle slightly rough, but rough enough for me to notice. I hope from what I'm reading here in the forums that this is "the break in period bugs" that will go away shortly, but I wanted to get the general concensus. Also has anybody noticed that the S model rear wheels seem to be tilted inward at the top ever so slightly. I noticed this on my car and a few others I drove behind on the highway ????

if the wheels tilt in at the top, that is indicitave of the camber settings - nothing to worry about.

My 05 Corolla idles rough as well. I have 2000 miles on the month old car and its probably about 50% highway, 30% two lane country and 20% 'city' driving.

The idle is still rough enough to feel inside the car at stops.

friendly_jacek

Hello all. Just curious. I recently (last week) bought a 05 Corolla S. I do alot of highway driving, and have 1300 on the odo already. The car seems to average about 27 mpg, and the engine seems to idle slightly rough, but rough enough for me to notice. I hope from what I'm reading here in the forums that this is "the break in period bugs" that will go away shortly, but I wanted to get the general concensus. Also has anybody noticed that the S model rear wheels seem to be tilted inward at the top ever so slightly. I noticed this on my car and a few others I drove behind on the highway ????

You are not alone. My car avarages exactly 27 mpg. Pure Hwy gets me to 30-31 mpg. When I drive slower than granny (RPM less than 2000) and without AC then I get the whoping 28 mpg.

I know there is something wrong with the car but cannot figure our what. Of course the dealership is of no help.

The engine used to sound like diesel when new. Now (18000 miles later), it is slightly better and I guess I got used to the sound a little.

The relatively poor MPG and engine sound makes me less than 100% satisfied with the car. I wish I had any answers for you but I don't default_sad .

Luckily (??) I have a rough idle but good milage. I try to keep the RPM's below 3000 when accelerating.

I read somewhere that when this guy switched from synthetic to conventional in his new Corolla, it increased engine noise and vibration.

EDIT : Maybe the rough engines cause the knock sensor to be overactive, retarding the timing and destroying fuel economy? Maybe take the car to a shop which can plug a scan tool in and see what is going on while the car is running...