Do I need to drive faster in the winter? :)

[Xist]

(weather permitting)

I drive 250 miles every Friday from Page, AZ to Show Low, AZ. It is supposed to be just over freezing when I pass through Flagstaff. I spend a surprising amount of that drive with my temperature gauge reading cold.

If I speed up, it will warm up, right? A warm engine gets better fuel economy than a cold engine, right?

I am not asking about speeding, sillies! Ninety-one miles of my route is the I-40, with a 75 MPH speed limit.

I only drive 65. Some semis pass me, but others only drive around 55.

What do you guys think?

I wish my OBD-II reader were working within specified parameters. Input! Input!

[redpoint5]

I would spend less of my life driving, partially by driving faster, partially by driving less.

Get a grill block. Is your thermostat stuck open?

[Stubby79]

Originally Posted by redpoint5

Get a grill block. Is your thermostat stuck open?

This.

And...65 is plenty enough wind resistance to make your engine work hard and get warm, in my opinion. It's not like you're cruising at 50mph with the throttle barely cracked open.

[Natalya]

ScanGauge II has engine temperature. Consider making either a grill block or a partial radiator block. I'm running a partial rad block in my G2 Insight right now to get it warmed up faster.

[samwichse]

Even my Insight will hold 92C on the interstate at 65mph in freezing temps. It really sounds like you have thermostat problems.

[jamesqf]

Originally Posted by samwichse

Even my Insight will hold 92C on the interstate at 65mph in freezing temps. It really sounds like you have thermostat problems.

Second that. Mine (with partial grill block - just a piece of coroplast stuck between radiator and A/C cooler) holds its normal 195 F on the level. It does drop down to ~140 going down mountains, but that's because it's mostly in DFCO.

[Xist]

Well, my extensive Internet research says that all of you are wrong and 75 MPH may not be fast enough.

Well, nobody actually wrote that, but that is more or less what the manager of the Flagstaff O'Reilly told me.

Forget that guy! He can do push-ups!

I found page after page of people saying the exact same thing. Can you imagine how boring that was?!

I just replaced the PCV valve and now I need to swap out the thermostat?! Why couldn't my $250 car have been reliable?!

Well, I did a thing, and my engine seemed to almost warm up in the 1.4 miles at 45° after lunch. We will see how the five-hour drive goes.

[ominous music]

http://ecomodder.com/forum/showthrea...ock-25986.html

[redpoint5]

Originally Posted by Xist

Well, my extensive Internet research says that all of you are wrong and 75 MPH may not be fast enough.

Well, nobody actually wrote that, but that is more or less what the manager of the Flagstaff O'Reilly told me.

I just replaced the PCV valve and now I need to swap out the thermostat?! Why couldn't my $250 car have been reliable?!

Well, I did a thing, and my engine seemed to almost warm up in the 1.4 miles at 45° after lunch. We will see how the five-hour drive goes.

http://ecomodder.com/forum/showthrea...ock-25986.html

I can get a Prius to full operating temperature well below freezing at 65 MPH in a few miles. It's not normal for a vehicle to fail to reach operating temperature on the highway at normal cruising speeds.

BTW- you never mentioned what engine coolant temps you're seeing, so how are we to know if you have a failing thermostat?

A thermostat should run you $10 and take 5 minutes to replace depending on how easily accessible/placed it is.

If you're grill blocking already, then you should easily be able to get the temperature where it needs to be. I would highly suspect a bad thermostat in this case, assuming your temperature gauge is functioning correctly.

[Xist]

My OBD-II reader stopped working, so I need to go off of the temperature gauge. I normally do not run the heater, but I recently tried when I got back to town, and it blew cold, so I imagine my sensor is good, but the thermostat is bad.

I already have it on my list when I get around to replacing my timing belt, but I think I will worry about studying for the GRE first. I finally take it on the 29th!

I just installed the grill block yesterday and I feel quite confused. I used to drive 600 miles per tank, but that slowly dropped to 500. Last week I replaced the PCV valve, drove 141 miles, filled up, drove 133 miles to Page, taped marine wrap over my grill and bumper, shrank it, and drove a total of about 320 miles before hitting half a tank--instead of 250, like my recent tanks.

We will see what my fuel economy is when I fill up, but it looks like I am running risk of getting 40 MPG at 40°, while my best tanks were in June and September.

The grill block is weird. On level ground, my engine seems warm, but not overly so, but I needed to turn on the heater when I climbed a hill!

There are worse things than running the heater when it is forty degrees, but I need to adjust the grill block.

[redpoint5]

I'm pretty much always running the heater in the Prius in the winter to keep the windows defogged. This runs 1 of the 2 cooling fans, which is usually sufficient to keep engine temperatures in the normal range even with a full grill block.

If I'm climbing a steep grade for many miles, the engine cooling fan might kick in with a full block. I'll open a strip up in the grill if I know I'll be operating at high load for an extended period of time.