Friendly reminder: CHECK YOUR TIRE PRESSURE! (It's getting colder in the north!) - Fuel Economy, Hypermiling, EcoModding News and Forum

MetroMPG · 11-04-2009, 01:44 PM

I'll admit I don't do it regularly enough.

But holy cow, I had a rude reminder to check my tire pressure this morning. I hadn't measured the energy usage of the last half dozen or so charge cycles in the ForkenSwift until last night's charge, and this one was awful.

396 Watt/hours per mile. One of my worst ever, in the 70+ cycles I've recorded. (Works out to about 85 MPGe using BTU equivalence - which is pretty lousy for an EV of this size.)

(For comparison, my "lifetime" energy use is 288 Wh / mile. That's measured at the wall (Kill-a-watt), from data for 70 charge cycles, and includes summer and winter driving - more summer than winter, though.)

So I checked the tires, and sure enough a couple were well down, ~13 lbs below where I normally have them. There were other contributing factors to the bad performance, but the tires were a big part of it.

Weather's getting colder (for those of us in the northern hemisphere)... So check your pressure!

vtec-e · 11-04-2009, 03:17 PM

Just had the weather turn cold here too. Must check them in the morning......while i'm servicing De Yaris. Woo hoo!!
I guess it's a case of "you know you're an ecomodder when you enjoy servicing your car"
Just not in the freezing rain though..........hmmmm

ollie

MetroMPG · 11-04-2009, 03:22 PM

Working on the car in the cold is definitely no fun. When I had my '89 Accord - which needed much more mechanical attention than the Firefly - I used to do a flurry (no pun intended) of maintenance tasks in the late fall in the hopes it would go through winter with no trouble.

Even just checking tire pressure when it's -10 isn't a pleasant little chore.

gone-ot · 11-04-2009, 04:17 PM

Quote:

Originally Posted by MetroMPG

I used to do a flurry (no pun intended) of maintenance tasks in the late fall in the hopes it would go through winter with no trouble.

...what most people label: "...scheduled/planned maintenance."

Johnny Mullet · 11-04-2009, 08:58 PM

All my vehicles are good to go. My Chevy truck has not lost even 1 LB of air in those new Buckshot Mudders I installed a few months back. We got another car also. A 1996 Monte Carlo with a 3.4L V6. All the tires on it were reading less than 20 PSI when I got it and serviced it...........

What's funny though is after the wife got this car, she really rushed me over the weekend to get the oil changed, brakes replaced, A/C Compressor replaced, etc and we took it for a ride and it was good. She put $10.00 in it at the gas station and said she was driving it to work. Monday she took it to work. Tuesday, I get out to get in my car and see her Geo Metro is gone and the Monte Carlo is sitting. I called her and asked........

"What's wrong with the Monte Carlo? I see you took the Geo."

She said..........

"That $10.00 we put in it is gone already. $10.00 goes all week in the Geo."

Mustang Dave · 11-04-2009, 09:15 PM

I checked mine this past Sunday. Overnight low was in the teens. They were about 2 PSI low.
Just a little cold weather maintenance...
Northern Arizona doesn't fit into most people's vision of Arizona.

newhavenpatriot · 11-04-2009, 10:02 PM

It's been getting steadily colder in CT, and the last time I filled my tires was October 16th. Between the time and the colder temps, they were down from 40 to 32 or so. Thanks for reminding me! Now they're happily at 40 again.

MetroMPG · 11-04-2009, 10:13 PM

Ran a bunch of errands in & out of town today in the ForkenSwift - man, it sure likes to coast more than it did yesterday. I guess it's true we don't notice change that happens very gradually.

Anyway, it's on the charger now. We'll see what the kill-a-watt says in the AM.

Quote:

Originally Posted by Johnny Mullet

She said..........

"That $10.00 we put in it is gone already. $10.00 goes all week in the Geo."

Great story, Mullet!