Just got my 2016 EX Fit two days ago. My previous car was a 2007 Fit, and there is quite a difference in the electronics package that I'm still getting used to.


Had a question about door locks. When I'm driving, after a time I can hear the door locks click to the locked position. Does that only happen when I'm driving? When I put the car in the garage the doors remain unlocked (I don't have the key on me). Is that working as intended?


Secondly, about the nitrogen in the tires. Never had a car that used this. As my husband has an air compressor and routinely would check tire pressure and top off when necessary, is there someplace I can also buy nitrogen to keep on hand or is everyone just using air?

 

As to the latter, I just use air. They were filled with nitrogen, but teh service tech said no issues with mixing it up.

 

Ah, we can tell you haven't read the manual. The manual states that the doors lock automatically once the vehicle reaches a certain speed. No doubt a safety feature to prevent someone from opening a door at speed and falling out.

As for nitrogen, it's a high price add-on by most dealers. I'd stick with air.

 

Thanks for the replies! I've *started* to read the manual, really! It's all just so new and I'm still in the overwhelmed stage. I'll stick with air in the tires; appreciate the confirmation.

 

i have been out of school a long time if i remember correctly i think the air we breath is mostly nitrogen

 

Nitrogens only real benefit on the street is that its usually "dry" so its slightly less susceptible to pressure rise from heat because there is no moisture to help it expand or to potentially corrode your wheels. You can pretty much get the same benefit by using a air dryer filter on your home compressor and they last years if all your doing is pumping up tires, if outside air is < 40% humidity it won't matter much putting it in your tires,,, we got along for years without it..

 

I run my tires on a premium blend of 78% nitrogen and 20% oxygen with smaller amounts of other gases.

 

Pegi, the door locking behavior is by default and normal. It can be changed by the user. I can't stand to have my door lock automatically so I set it not to do anything when the car is in motion. I did leave the unlock all doors when placing the car in park. If you don;t like the way that operates you can change the defaults.

 

Or some wannabe carjacker from snatching any door open at a stop light or sign. The door goes "click" at about 10 mph.

 

That's a shame you're stuck running on nitrogen and oxygen. You might want to spend a bit more on exotic gases.

I'm using straight unicorn flatulence and the added benefits in increased MPG are just mind bending.

 

nitrogen is less likely to migrate through tire rubber than is oxygen . . .

When you put air in your tires, the oxygen molecules escape first thus concentrating nitrogen in the tire.

 

So eventually if you keep topping off it will be all nitrogen and not cost a cent..

Seriously , I've played around with this, at the track I lose gain and lose the same amount of pressure whether I did nitrogen or air. The best option I ever found was buying a simple cylinder of compressed dried industrial grade air. It comes at scuba pressure and a mid size tank will air up about 100 tires.. I even ran a pneumatic wrench with it..

 

You can program the behavior of the door locks to a point. I just turned off the auto-locking/unlocking entirely as it was a pain. I supposed if I were paranoid about carjacking I would want it, but I found the doors to be locked when I wanted them unlocked more often than not.

Nitrogen leaks through rubber less than oxygen? O2 is 2.96 angstroms while N2 is 3.16 angstroms. Not a significant difference!

The real reason that N2 is popular in tires goes back to aircraft. High pressure nitrogen (hundreds of PSI) was used to inflate the oleo struts of airplanes. At this pressure oxygen would react with the oil. so pure nitrogen was needed. Aviation mechanics would have high pressure bottles of nitrogen to service oleos.

A lot of these mechanics also raced cars and motorcycles. They found that the high pressure bottles were convenient for inflating tires and running air tools away from a compressor. Over time, the legend about nitrogen being a better inflation gas grew from this practice. After all, if the Ferrari team is inflating tires with nitrogen there must be an exotic reason, right?

 

O2 "permeates" approximately 3-4 times faster than does N2 through a typical rubber, as is used in tires, primarily
because O2 has a slightly smaller effective molecular size than does N2.

 

Yep you can buy a nitrogen generator for your shop if you need a lot. uses permeable membrane tech to do the work.

What gets forgotten is that if your driving hard, IE hard enough to soften the rubber on our tires, your tires are outgassing petroleum vapour. It contaminates whatever is in the tire and its way worse about expansion under heat, on race tires I break the bead loose and flush the tire out (If its a tire that lasts more than a day or two.. ) I had a client that was a die hard nitrogen fan so I put an extra valve stem on all the wheels so I could bleed the tires easier. I'd just hook up a cylinder and open the other valve stem and let it run for a bit then close it up. Hoping I was flushing the majority of the moisture and regular air out and leaving the nitrogen in.

 

Air is 80% nitrogen. Let's assume that you fill the tire with air to 32PSI and all that nasty oxygen sneaks out. That leaves the car at 26PSI. Reinflate to 32 PSI and you now have 96% nitrogen in the tire. Let all the oxygen leak out again and you're only down to 31 PSI!

Now, you are unlikely to allow the tire to get that low, but the same math works with smaller adjustments. If you accept the "oxygen leaks out faster" myth you also have to accept that the tires will soon be full of nearly pure nitrogen!

My real-world experience is that tires lose about 2 PSI per month in normal use no matter how many times their pressure is adjusted. That, and the very similar molecular radii of N2 and O2 tells me that filling tires with nitrogen is selling snake oil


Oh, and remember that tires are filled with air at 14.7 PSI (absolute) when their gauge pressure is zero. Put in nitrogen to fill the tire to normal pressure and you still have 1/3 normal air. Unless your car has purge valves on opposite sides of the wheel and the person filling the tire is willing to waste a lot of nitrogen in purging the tire the use of nitrogen is pointless.

 

After the public caught on the the overpriced scam of paint protection and undercoating that dealers were flogging as big profit item for themselves, dealers were looking for new high profit ideas that they could promote to gullible buyers at closing time. The anti-theft etching thing helped a bit and the nitrogen filled tires nonsense was another thing they tried, with mixed results. For a typical passenger car there is no real world advantage to filling the tires with nitrogen. And there's no shortage of snake oil being flogged at your local car dealership/shop. I can hardly wait to see what they come up with next.