infiltrator

read the review that is posted on that link. it will give you all the info you need. i can see a significant increase in response in my engine if i let it warm up, compared to if i just turn it on and go.

you see, im not sure about out there, but in southern cali, the min speed limit is about 50 (on city streets)... so its like, you jump on that highway, if my truck isnt warmed up, it doesnt go as good as it would normally. thus my reason for letting it warm up.

id rather let it warm up for that extra couple minutes, and be able to drive normally, than to feel my engine almost struggle.

Dare44

probably just the combination of u switching oils and winter gas

BigSquatch

ok enuf talk about warming up the truck, thats irrelevant now. im warming it up for a min or two.

fact still remains. truck runs fine. 2000 with 61k.
NO CEL. replaced o2 sensor. possibly running rich. 12 mpg??
what should i do besides basic tune up?? something is wrong. horribly wrong.

Texas_Ace

Tried getting gas someplace else?

I would try some seafoam (in the intake not crank case), it can't hurt.

Then some gas additive would not hurt either. Rxp can work wounders too.

About the last thing that comes to my mind.

X-AWDriver

I didn't review the whole thread but did you check your TPS. Mine threw that CEL 5 times back in October but then hasnt' returned and my TPS checked out fine but i have my suspicion that the colder weather is masking the problem but still is the problem.

BigSquatch

that is the only other thing that is coming up in my searches. How do you check your TPS?? its possible it could have thrown a CEL before i got the truck and i just dont know about it and hasnt come back. frustrating to say the least.

BigSquatch

wouldnt a bad tps make the truck run bad?? truck seems to run fine.

JGrauman

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JGrauman

after driving my 98 auto 3.4 v6 for the first tank of gas, i'm getting 15mpg. with my 94 5speed 3.0 v6, i was getting 17mpg. that's pretty much a 50/50 mixture of hwy and city. i was a little disappointed in that drop and hope it's due to the cold air. i was kinda hoping to see an improvement, i just bought some injector cleaner (probably a waste of money) to see if that would help.

BigSquatch

well should i spend the money and take it to the dealership and see what they can diagnose?? id rather not but im running out of options. They will prolly try to hose me.

Texas_Ace

And won't do any good i bet.

My personal thought is that the bad MPG is a mixture of a lot of little things all adding up.

Try to find a trustworthy mechanic around and i would take it to him. I am soooo lucky to have a guy i have used for almost 15 years and trust.

infiltrator

is your e-brake on?

jk, were running out of options here lol.

FavreRunner

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youngbuck

You are not suppose to let your engine idle cold for long periods of time. Let the vehicle run for about 1 minute on a really cold day, and then immediately start driving, but drive easy. By that, I mean no hard accelerating and no high RPMs (I keep mine below 3k). On a warm day, let it idle for 15-30 seconds before taking off.

When you first start your vehicle up when it's cold, it's running in closed loop, with no feedback from your O2 sensor. That means you are running rich. Not only does this mean more fuel consumption/waste, but also increased fuel dilution of your oil!

It is definitely best to simply let it run for a short period to get things flowing, and then take off slowly, and drive easy until oil temps increase. This will increase engine life, and give you better gas mileage. You want to get your oil hot as fast as possible, while at the same time not driving hard when it's cold (highly increased engine wear).

10-15 minutes idles in an attempt to warm things up are definitely bad for your engine life, and does nothing to warm up drive-train fluids as others have mentioned (though if you have a 5 speed and it's running in neutral w/ clutch out there are at least some parts moving.