03 poor mpg,s=

[jamesmetairie]

2003 corolla with about 90,000 miles. getting 21mpg in city with a/c on. what would you check first maf and iat?? what is iat? idle air??

[rsirois]

21 MPG isn't too bad if it's in a dense city with speeds averaging under 25 with the AC running.

I'd check my air filter and tire pressures first. After that I'd run it on the highway for over a half hour with some fuel injector cleaner in it.

[holler1]

Can't answer your question directly, but yesterday I found a thread on cleaning idle air control valve (IACV), PCV and a bunch of other related areas. http://matrixowners.com/?showtopic=65513
This is for matrix but I think the engine is the same since the IACV looks identical to the 03 Corolla I am checking out for my daughter. BTW I saw your question about engine temp and my sense is that the temp gauge is not sensitive or rapid enough to pick up fan cycles. Someone also verified that the temp gauge sitting at about 8:30 on a clock face is about normal. I'm envious of your of AC in Metairie; it's about 4 F here.

[jamesmetairie]

my wife likes to use the a/c on max(recirculation) all the time ,even in winter to keep gas fumes from entering our car. using a/c in 40 degree weather ain,t green.

[huangxin]

Originally Posted by jamesmetairie

my wife likes to use the a/c on max(recirculation) all the time ,even in winter to keep gas fumes from entering our car. using a/c in 40 degree weather ain,t green.

why not just turn the air on but keep the A/C off? it would circulate the air inside the car without burning extra gas

[jamesmetairie]

we just got this car recently. the old lumina had to have a/c max.

[JasonA]

In addition, if it's cold enough (usually around 40*F or below), the A/C won't engage anyway. The ECU locks out A/C compressor operation in moderately cold ambient temperatures under the assumption that the air is dry enough anyway at those temperatures, and the A/C won't really be effective.