my c in the cold

tire pressure was low, nothing is in the back seat area

 

Last week my tire pressure was 40/38, and I rose it to 42/40. Since then, the ride has been smoother and my car glides longer.

The tires on my previous hybrid (the one before the accident) were Bridgestone and had a maximum pressure rating of 44.
The tires on the current one are GYs and have a maximum pressure rating of 51.
I have them currently set at 42/40 like you, but there are so many potholes around here, I'm not sure if you would recommend going to 51/49, in case a big bump or something blows the tire.

 

I got a single trip best of 64.4 mpg one afternoon. Every morning still is the worst, today barely got into the low 40s. This tank has about 54 miles on it and is averaging about 48 mpgs so far, all city driving to/from work

 

So do you guys think I should inflate my tires to 50 psi or leave them in the low 40s?

 

I've been driving at 44/42 for about a decade. Try that.

 

Though it only got down to mid-teens here and thus no problem starting either I did have a cocern avbout the low temperature of the 'hot' air from the heater. So we blocked off the center 4 x 4 'slots in the middle of the grill, leaving the two outer vertical rows open; apparently that restricts enough air flow to the radiator to raise the recycling temp to at least 190F. I guess the minimum flow through the thermostat is not enough to raise the recycling flow to at least 180F. Thats based on thermo tabs rated at 180F and 220F (104C) on the radiator hoses and on the battery face just in case. If you want to try use foam pipe insulation cut in legths about a quarter inch wfder than the 'slotr'; stacking the insulation pieces in the slots will effectively close off the air flow except for the outer 'stacks' of slots in the grill.
When the temperature rose to the low forties there seemed to be not much difference in the radiator temperature or heater air. Then pieces of insulation come off easy and are easily reused. The fact they are black fit right in the appearance.
BTW thermo tabs are stick-on labels that turn solid black when the stated temperature is measured. Great stuff in the prototype lab. They come from a variety of suppliers including most lab supply houses.

 

Leave them in the low 40'sfor best results unless you're in a economy competition. 175 section tires aren't wide enough to benefit from higher tire pressures over 40 psig in normal driving. Or track either.

 

Alright, well I've done just that for the last 2 months straight, with the tire pressure set to about 42 psi. On a warmer day the tire pressure can be a little higher (like today, 44 psi).

The extreme winter totally destroyed the roads around here. It's like driving on an obstacle course, and some of the bumps I've hit give me a migraine... but even with high tire pressure, my hybrid seems to be holding fine at 42-44 psi.

Other than the bad roads, the ride actually feels smoother than when I had the tire pressure at 38-40 psi. Since going to 42-44 psi, my fuel economy is about 5%-10% higher, and my glides on all electric are waaaaay longer.


I should probably just mention that we've had so many sub-zero mornings and weeks straight of below freezing temperatures. My "winter lifetime" fuel economy for this season is 44 mpg.

 

During the worst of the weather, I was getting low 40s mpg-wise on my daily commute (7 miles, city), with almost-full grill blocking, tires at 50 psi, and heat off (except minimal defrosting). During the above-zero parts of the winter, I usually get 50-55, and when it's dry and above 50 degrees I get 60-70mpg. In the worst of the cold, my c (parked outside) took an extra ~0.5 seconds to start and the ICE only turned off like 5 times for 5-10 seconds each before turning back on due to the cold.