20
votes
Accepted
Checking Tire Pressure when the tire is warm or cold
Cold. All OEM's door placards specify the tire pressure be set when the tires are "cold". But what is cold? From a random Honda owners manual:
Measure the air pressure when tires are cold. This
means ...
- 11.6k
18
votes
Accepted
Should I fill my tire?
Yes, you should fill your tire. The fact the other tires all are nominally correct means you should trust your gauge.
Modern tires often have reinforced sidewalls that mask the appearance of low ...
- 2,159
15
votes
Accepted
Why nitrogen and not carbon dioxide is used in critical tire applications?
Nitrogen is inert and doesn't affect rubber or the steel rim.
Carbon dioxide is highly reactive and affects both the rubber by causing swelling in the rubber. It also would cause corrosion in iron ...
- 3,917
15
votes
Why is it that when supercharging, it's preferred to compress the input, rather than pull a vacuum on the exhaust?
The power of an engine is not determined by the difference in pressure between the combustion chamber and the exhaust. Power is determined by how much energy one can put into the combustion chamber ...
- 4,455
13
votes
Should the inflation pressure for low profile tires be the same as for regular tires?
In almost all circumstances you should use the manufacturer's numbers as your guide. They are aware of the requirements of their wheels, and they do understand that a low profile requires a certain ...
- 18.6k
13
votes
Tire pressure with load and heat
As long as you are running Light Truck (LT) tires, you should be just fine. Manufacturers take into account the tire pressure is going to go up due to heat buildup. This is why you check tire ...
- 153k
12
votes
How To Pump Up Car Tires (finding the optimal PSI for your tires)
On every car sold (that I'm aware of) there is a sticker pasted, usually in the door jam of the driver's side, which states exactly what the car manufacturer suggests your tire pressure should be at. ...
- 153k
12
votes
Why nitrogen and not carbon dioxide is used in critical tire applications?
Nitrogen makes up around 80% of Air - therefore its more readily reclaimed and separated than the smaller amounts of other gases in air. I.e. the process for reclaiming nitrogen from air could be ...
- 2,655
12
votes
Why is it that when supercharging, it's preferred to compress the input, rather than pull a vacuum on the exhaust?
OP's question states:
It should follow that turbocharging should be equally effective pumping air out the exhaust, than in the inlet.
No, it is not as effective.
You can't reduce the pressure to ...
- 1,848
10
votes
Difference between fuel pressure and fuel rail pressure
On a car with fuel injection there can be two fuel pumps, one high-pressure and one low-pressure. The low-pressure pump moves the gas from the tank up to the high pressure pump. The high pressure ...
- 895
10
votes
Accepted
How does tire pressure affect susceptility to hydroplane?
In this article by the NHTSA a formula is given for calculating the speed at which a tire might be expected to hydroplane. The formula assumes "...the water depth exceeds the capability of the tread ...
- 1,502
9
votes
Accepted
Direct Injection Injectors - How do they prevent blow back into the fuel system?
I will try to answer this as best as possible. There are a few factors that come into play here (Mainly the manufacturer of said engine).
Direct injection petrol engines work much like a diesel. You ...
- 3,343
9
votes
Direct Injection Injectors - How do they prevent blow back into the fuel system?
In cylinder pressure is in the 200 psi range. GDI fuel pressure is varied from 500 up to around 3000 psi. This alone is enough to keep fuel blow-back to a minimum. Carefully engineered injector pintle ...
- 11.6k
9
votes
Accepted
Why is it that when supercharging, it's preferred to compress the input, rather than pull a vacuum on the exhaust?
IMO this is not a stupid idea, however it doesn't actually make sense for multiple reasons:
A naturally-aspirated Otto or Diesel engine by itself doesn't expand the gas even to atmospheric pressure. ...
- 435
8
votes
Does free revving a diesel engine to 4000 rpm (1.6 crdi- hyundai) cause any damage?
Short answer - no. It's perfectly okay. And , it's also perfectly okay to be annoyed. It's one of those things mechanics like to do (no offence to anyone). Similar to endlessly hitting refresh on a ...
- 2,196
8
votes
Accepted
Low-side and high-side pressures lower than expected after AC repair
That chart is not universal. You should be fine.
Every model will have its own characteristic low-side and high-side pressures.
This is why some manufacturers recommend charging refrigerant by mass ...
- 39.1k
8
votes
Accepted
Should the inflation pressure for low profile tires be the same as for regular tires?
tl;dr: it depends. Usually bigger wheels + thinner tires = higher pressure.
So, should one keep the pressure to what's recommended by the manufacturer regardless of the tire dimensions?
Sort of. ...
- 24.3k
7
votes
Should I fill my tire?
Because you have verified the gauge is working reasonably by trying the other tires, go with the gauge. Your owners manual will have the inflation pressures for your car. Just make sure that the ...
- 9,326
7
votes
Accepted
Does high air pressure throw off wheel balance?
No. Balance is caused by even weight distributed around a tire.
If there is more weight in one spot the tire will "wobble" when spun.
Inflating a tire more may alter the diameter, but the weight of ...
- 1,552
6
votes
Should I fill my tire?
Generally speaking any time your tire pressure is more than 10% over or under the ratings I would definitely correct the pressure ASAP and check the tread wear too. In your case 10% is 3 or 4 pounds ...
- 161
6
votes
Accepted
Tire Pressure Adjustments When Needed
DON'T reduce tire pressure
In fact, the recommended thing to do here would be to increase tire pressure if there is more load expected on the vehicle.
Have a look at this tire pressure placard for ...
- 39.1k
6
votes
Accepted
Why does a tire have the same air pressure when mounted on the car and when not?
The very short answer is this: for a gas at constant temperature, the product of pressure and volume is constant. This is the ideal gas law - close enough for this purpose.
When you load a tire, it ...
- 186
6
votes
Showing Oil Pressure When Engine Cold and Not Running
You could be correct with a bad sensor, or possibly, a corroded connection (vibration making the contact) or a broken wire or a faulty contact in the ignition switch. That's the fun (!!) with ...
- 34.6k
6
votes
Why is it that when supercharging, it's preferred to compress the input, rather than pull a vacuum on the exhaust?
There is no direct path from the intake to the exhaust, at least one set of valves will be closed at all times. The exhaust valves open and the piston pushes the exhaust out of the cylinder, then the ...
- 16.2k
5
votes
Accepted
What could be causing the rapid loss of tyre pressure?
Obviously, this can be anything.
leak in the new tire
even a leak in the rim
leak between tire and rim (may be there's some dirt on the rim or a burr on the tire)
leak between rim and valve stud
...
- 7,047
5
votes
How To Pump Up Car Tires (finding the optimal PSI for your tires)
Something else to be watch out for, if you filled the tire to 44 PSI while the weather is cold and the tire is cold from not being driven, as soon as it warms up, the tire warms up, and so does the ...
- 9,326
5
votes
Showing Oil Pressure When Engine Cold and Not Running
When you start most vehicles and motorcycles are not an exception to this, all of the display lights are lit indicate that they are all working. If something is not "ON" then it's very possible that ...
- 371
4
votes
Accepted
Radial tires: Do they bulge at too high pressure?
The answer is simple: depends. It depends on the manufacturer's choices in how they reinforce the sidewall and how that is tied in to the belts under the tread.
One should not expect an off-road tire ...
- 2,159
4
votes
Accepted
How To Pump Up Car Tires (finding the optimal PSI for your tires)
Correct Tire Pressures
As @Random832 mentioned in the comments, the information for my 2004 VW Passat B5 was not in the door jam of the drivers' side, but rather it was actually on the inside of my ...
- 7,927
4
votes
Should I fill my tire?
Your description "front driver looking flatter" suggests that the front driver and rear passenger tires could be carrying more load than the rear driver. If the front driver and rear passenger are on ...
- 71
Only top scored, non community-wiki answers of a minimum length are eligible