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Old 12-29-2014, 10:48 AM   #36 (permalink)
Miller88
Master EcoModder
 
Join Date: Jul 2008
Location: NY state
Posts: 501

XJ Cherokee - '00 Jeep Cherokee Sport
90 day: 12.96 mpg (US)

FoFO - '11 Ford Focus SE
90 day: 36.78 mpg (US)
Thanks: 1
Thanked 51 Times in 38 Posts
Quote:
Originally Posted by Grim View Post
I didn't see a single person mention this little tidbit of what really drove that don't warm up statement.

It's not about your car lasting it's about getting that car to operating temp as fast as possible to drop emission levels. The cat will never get to operating temps in a cold climate at cold idle when the engine is running a rich mixture. That statement was EPA driven.

The owners manual on my BMW k1100 motorcycle that's equiped with a Cat point blank warns of damaging the cat by long warm ups before driving.
I wait till I'm up to at least 80f on the scan gage and thn I slowly drive out of my hood Trying to keep the RPMs down while the oil is thick. Thick oil will be bypassing
My (former) '01 Taurus, father's 01 F350 5.4 and my '11 Focus idle at asinine speeds to light the cat off ASAP. They all will shoot to 2500RPM on cold start. When the exhaust fell off the pickup, that thing would wake the dead when it started and idled at 2500RPM.

The Focus and the F350 are manual transmissions, and they'll go along 30, 35 MPH with your foot off the gas in 5th gear until the cat lights off. The most annoying thing is, they refuse to idle below 2500RPM when moving. Makes shifting on a cold morning nearly impossible.

My Taurus would go about 15MPH or so shifting into 2nd and sometimes 3rd with no throttle applied.

My Jeep doesn't do that ... I could see it destroying the cat idling for a long time


Quote:
Originally Posted by jcp123 View Post
Even before I got into fuel economy, I thought it was a bit silly to idle the car to warm up. But then, I did grow up in California.

Back to that t-stat conversation, I did replace the t-stat in my Mom's Mazda3 (Duratec 23). The thermostat was fairly expensive ($30 I think?) but nowhere near $200. Came from AutoZone. It took a bit of hassle, but I was able to replace it without removing anything else at all. Don't fear it!
It's an all-in-one. From Rock Auto, looks like I can get either a 180 or 203 thermostat for $89. I just don't know what is ideal operating temp. I don't want to ruin anything by running it at 203 all the time ...
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