You do not have to warm up the truck for that long. Doesn't matter how cold it is, really. I just turn it on, then go. Of course, I do take it easy until it's fully warmed up, but driving right after starting does not hurt anything. In fact, the M3 manuals state that "warming up" is NOT recommended. I'll have to check the 4Runner manual to see if it says anything about that.

 

even when it's only in the low 20s where i'm at and before i go hunting in the mornings, i let my 3.4 idle 3-5 minutes, which is plenty to get the oil and coolant up to temp, making the motor happy with the oil and me happy with the heat... so i say let it warm up about 5 minutes each morning, and that will help get some mpg back...

 

•An idling engine releases twice as many exhaust fumes than a vehicle in motion.
•No more than 30 seconds of idling is needed for oil to circulate through your engine. Many components, such as the wheel bearings, tires and suspension system will only warm up once the vehicle is moving.
•Restarting your car many times has little impact on engine components, adding only around $10 per year to the cost of driving, money that is recovered in fuel savings.
•Ten seconds of idling uses more fuel than restarting the engine.
•Idling can damage your engine since it is not operating at its peak temperature where fuel is completely burned. Fuel residue from incomplete burning can damage engine parts.
•Idling a vehicle for 10 minutes a day uses an average of 100 litres of gas a year. If gas costs 70 cents a litre, you will save $70 per year, just by turning your key.
•A block heater warms the oil and engine coolant, making it easier to start your vehicle and improving winter fuel economy by as much as 10%.

 

either way, im still getting 12mpg on the road. im praying itll be the easy o2 sensor fix.

 

Still no eveidence of anything wrong but I think I'm going to change my TPS anyway since it is a cheap fix and that;s what my CEL was when it was throwing it back in October.

I was getting 16-17 and now it's dropped to 14. I'll get back to this thread when I find anything.

On idling your truck (which I try to do for no more than 2-4 minutes on really cold days) it will not use excessive fuel idling for 10 minutes. My mom locked her keys in her '92 Bronco and it idled for an hour and a half before she got a locksmith to open it and she had a full tank when it was started and it used a 1/4 tank in that hour and a half.

 

How is that not using excessive fuel when you're getting 0 MPG? You do not need this "warm-up" period. All the fluids reach the critical parts of the engine in less than 30 seconds. All you're doing is polluting the environment. Plus people tend to "warm up" their cars and then drive off like they just stole the thing. They don't realize that nothing in the driveline got "warmed-up."

 

ok i just warm up my truck to actually WARM UP THE INTERIOR, cuz its dang cold here. i know that technically its best to just start the car and go, keeping the revs low and taking it easy. So im not actually worried about fluids and whatnot.

 

My neighbor does this all the time to all the vehicles he drives.........best part.......he owns his own mechanics shop.

 

Letting a vehicle idle while warming up will absolutely kill your mpg average.

How about experimenting before buying the O2 sensors and just get in and drive. See if the mpg improves. If it does, you've saved money on the sensors and will have that much more $$$ to buy gas.

 

already have, still getting horrible mileage. ordered o2 sensor anyway.

 

cool... I'd be interested to know what difference you see after you change out the O2 sensor. Please post your results in this thread when you get a chance.

Mahalo

 

hoping to get it in the mail tomorrow and get it swapped out. Ill post up results.

 

welp, getting pretty much same mileage. ugh.

next on the list
clean maf? what else can make my mileage drop so significantly?

 

Letting it idle for 15 mins before driving......

 

cleaned the MAF, still getting 12mpg.

noticed the tailpipe does look slightly black, not SUPER black but black.

 

Unless I missed it, no one has mentioned tire pressure. Have you checked the pressure since the weather became cold? Mine was down over 5 lbs. That can have a significant effect on mileage... And tire wear, ride quality, etc.

 

it doesnt matter if the oil gets to the engine parts, if its not warm, its not helping..

please read (anyone who thinks all you need is 30 seconds and then vroom your off...)

https://www.yotatech.com/forums/f2/c...friend-124912/

 

tires should be fine, suckers would have to be near flat for me to be getting this kinda mileage.

 

Read that post again. No one is saying you should just jump on the throttle and go. You do need to be easier on the engine while it warms up, but you do little good just letting an engine idle. 30 seconds is more than enough time on all but the coldest days. By coldest I'm talking less that 0 degrees F. The colder it is, the easier I am when driving the vehicle, in general. The differential oils can take a long time to heat up.

You engine oil doesn't get to 212 degrees just sitting and idling, anyway. Cold oil lubricates, it's just not as good as nice hot oil. That last sentence could be taken wrong in the wrong forum.

MadCityRich

 

lol! The truck is three inches lower!

I was thinking it might be a combination of things. Low tire pressure + Warm up time + Winter blend = MPG