Same recommended warmup procedure regardless of driving distance (ie short idle then drive). I should also add, I'd leave the climate control off until the temp gauge is in the middle. I know it's painful, but the auto climate control has a tendency to try and warm up the interior as quick as possible even when the coolant temp is low (warm coolant is what provides interior heat). The more heat you can give to the engine at first, the quicker it will warm up and the hotter the air from the climate control when you turn it on.

 

I was just thinking if I should leave it on until it reaches the "normal operating temp" or just shut it off when I get there. Usually when I get to work it is about 1/4 of the way up, or halfway to operating temp. My climate control always stays on low until the car warms up, otherwise it's just blowing cold air for a while...

 

I'd just shut it off. Either way, it's not particular good for fuel economy or cat life. An idling motor isn't an effective way get the cats to full operating temp so that they can burn off that rich hydrocarbon during cold engine operating. High load situations is what will light the cats off.

 

thanks for the opinion!

 

This is why I want a heated garage, won't really help after a 8 hour day of work though.

 

Haha don't we all want a heated garage. All I have to say is next year for school I am looking for a garage that would be worth heating. This one is way to sketchy and falling apart to waste money trying to heat it.

 

[quote=slim17265;6237294]+1

You shouldn't need new plugs at 90k miles. Assuming, of course, the '04 came with the platinum plugs. I don't know that for a fact.

Where do you live it's already so cold out? I've driven my car at subzero temps quite a bit over the past couple years, and have almost as many miles as you do, and it's never had a problem starting up. Have you ever changed coolant/flushed the radiator? Could be something with that system.

 

^ 90k is pretty much close to the Change interval, Id change out the spark plugs engine air filter and see how that does it. And as always check for proper inflation.

 

lol.. what MPG are you getting?

if you are getting 25 mpg.. vs 27 mpg in the summer... there is no problem

 

Four of the seven Nissan (Infiniti) vehicles I've owned eventually had thermostats stick open. I'm waiting for my '05 Max and '06 G35x to need new thermosats next year.

 

Well in the summer I was getting about 23 mpg highway .. But now I'm getting like 16 mpg and I'm in nyc so its not even that cold over here yet ... But I recently just got a tune up and changed my fluids .. My mechanic looked at my sparks and said there still the oem ones but that I should change them after the winter.. I also have my tire pressure light on and my tires are kinda bald I'm going to get new ones soon .. Could this be affecting my mpg that much?

 

I agree with everything you said and have explained in this thread except for that. Yes the motor does warm up faster but you run the chance of cracking your cold windshield by turning on your climate control when its already at normal temperatures.

 

You do a lot of city driving In New York? That could be the cause right there. That city is nasty to drive through or in the surrounding areas.

23mpg doesn't sound to out of line for an x. I think a buddy of mine gets 24 when going about 75-78 on the highway.

If your tire pressure is low that could account for the lack of 1 maybe 2mpg depending on how low they are.

 

Did you see this issue overnight? Or have you a noticed a gradual decline over the past couple of months?

A sudden decrease would mean something is wrong. A gradual one could most likely mean a few things.. including tire pressure, change in driving habits, colder temps, etc

Mine dropped from 19-20 to 12-13 but that's because of a severe engine problem.

 

[quote=thebonafortuna;6239917]
I disagree for a couple of reasons.

1) I've pulled out OEM platinum plugs on 85-105K VQ motors and the electrodes were heavily warn, increasing the gap dramatically. All these cars were experiencing minor driveability issues and low mpgs.

2) The longer you leave the plugs, the more likely you'll have problems removing them. The last thing you want to have happen is heavy carbon buildup on the plug end getting pulled into the threads, causing a potential cross-threading issue.

3) The heads are aluminum and the sparkplug thread is steel. Chemical reactions take place between these two different metals. The longer you leave them in, the higher the chance of the cross-threading issue to occur.

The maximum I'd ever leave a set of plugs in aluminum heads to 4 years or 60K miles. No more.