clueless about cars a couple of questions

[sms747]

First one, what tyre pressure is it for a Toyata Vios? looking on the web it says 30-33 psi but on the wheels (Goodyear sport) it says 51psi, which should I go with?

Gas, mrs started putting in E20 at petronas stations, now she says E91 is better is that right? for some reason she thinks you can only fill up at petronas stations and not others like shell?

[arthurwait]

Is 51 the max pressure written on the side walls ?

Go with what it says on the web or better still what it says on a plate probably on the door opening.

The petrol is basically the same everywhere, if your car is capable or using a particular fuel it doesn't matter where you buy it.

Over to Trams Am and Warpspeed.

[Ace of Pop]

Is 51 the max pressure written on the side walls ?

Go with what it says on the web or better still what it says on a plate probably on the door opening.

The petrol is basically the same everywhere, if your car is capable or using a particular fuel it doesn't matter where you buy it.

Over to Trams Am and Warpspeed.

OMG, not Tran Am with his Nearly Famous Pressure Gauge . .

[anon210]

Is 51 the max pressure written on the side walls ?

Go with what it says on the web or better still what it says on a plate probably on the door opening.

The petrol is basically the same everywhere, if your car is capable or using a particular fuel it doesn't matter where you buy it.

Over to Trams Am and Warpspeed.

OMG, not Tran Am with his Nearly Famous Pressure Gauge . .

BTW, you can add me to Transam... i also have now a pressure gauge (to check I am not underinflated!).

[sotsira]

30-33 psi sounds about right, but if you have an owners manual it

will state the tyre pressures in there.

The 51psi on the tyre sidewall is the max safety pressure.

Also remember that the tyre pressures should be checked when the

tyres are cold as the pressures rise when the tyres warm up after being driven.

[Gsxrnz]

Go with whatever the label says inside your drivers door frame. 30/33 sounds about right. However, be aware of the time of day and ambient temperature when you set the tyres. If you set them on a warm day after the car has been sitting in the sun, or if you've been driving for a couple of kilometres, inflate the tyres a few PSI extra to compensate for the heat effect of giving a false reading.

If you set the tyres in the evening (say ambient temp of about 25-28), set them as per manufacturers recommendations. During extreme weather conditions (extra hot or extra cold), recheck and reset as the pressure could move 1-5 psi's quite easily.

Or.......do what most people do and pump them up when they look a bit on the flat and saggy side, every three months or so.

[Ace of Pop]

Is 51 the max pressure written on the side walls ?

Go with what it says on the web or better still what it says on a plate probably on the door opening.

The petrol is basically the same everywhere, if your car is capable or using a particular fuel it doesn't matter where you buy it.

Over to Trams Am and Warpspeed.

OMG, not Tran Am with his Nearly Famous Pressure Gauge . .

BTW, you can add me to Transam... i also have now a pressure gauge (to check I am not underinflated!).

But once they know you have one , you get asked to check for them, im about to give mine away.

[richard_smith237]

Nitrogen ??

[Ace of Pop]

As an aside, Tuna Drives use them to see if their EGO is Overinflated

[VocalNeal]

Also remember that the tyre pressures should be checked when the

tyres are cold as the pressures rise when the tyres warm up after being driven.

So if pedantic you'll have to buy a tire gauge and check them at home before driving if a bit low remember how low then when arriving at the gas station (tell the wife she needs to go to one with a compressor) check the tires again and add the amount they were low to the amount you measure at the station.

Or do what 98.8% of the planet does arrive at the gas station and pump them up to 33psi or 2.2 bar or 227 Kpa whichever pressure the unit at the gas station is calibrated in.

If Thai 51 is correct. Under inflated tires cause poor fuel economy so therefore over inflated tires must save fuel. If you see 22" rims on a Fortuner it will not be the tires that are over inflated!

Edited June 21, 2013 by VocalNeal

[Woodsie888]

As an aside, Tuna Drives use them to see if their EGO is Overinflated

Over inflation often leads to a necessary 'pressure release' which is a good thing.....................

[aussiebebe]

If you're really interested in tire pressure, OP, the only place I've ever read about it being seriously discussed outside of racing is a site called ecomodder which is for people who are interested in fuel economy. They won't over-inflate tires (ie not beyond the maximum 51psi of your tires) but they will inflate them enough to improve fuel economy. In other words, 32psi is fine for normal driving.
About the fuel, I also have an E20-compatible car the Honda City. Your wife might be right about E91; you see E20 is 20% ethanol and 80% gasoline while E91 (Gasohol) is just a baht more per liter yet as it contains just 10% ethanol so you are getting 12.5% more gasoline. This may give you better fuel economy and be better for your engine. I've tried a tank of two of E91 and not noticed a difference but my car's only a 1.5l.

Edited June 21, 2013 by aussiebebe

[WarpSpeed]

Is 51 the max pressure written on the side walls ?

Go with what it says on the web or better still what it says on a plate probably on the door opening.

The petrol is basically the same everywhere, if your car is capable or using a particular fuel it doesn't matter where you buy it.

Over to Trams Am and Warpspeed.

Nope, I'm done regarding this topic, it seems to be too complicated for some to grasp the concepts explained in great detail ..

OP, the recommendations are in the owners manual most likely ..

Edited June 21, 2013 by WarpSpeed

[WarpSpeed]

Also remember that the tyre pressures should be checked when the

tyres are cold as the pressures rise when the tyres warm up after being driven.

So if pedantic you'll have to buy a tire gauge and check them at home before driving if a bit low remember how low then when arriving at the gas station (tell the wife she needs to go to one with a compressor) check the tires again and add the amount they were low to the amount you measure at the station.

Or do what 98.8% of the planet does arrive at the gas station and pump them up to 33psi or 2.2 bar or 227 Kpa whichever pressure the unit at the gas station is calibrated in.

If Thai 51 is correct. Under inflated tires cause poor fuel economy so therefore over inflated tires must save fuel. If you see 22" rims on a Fortuner it will not be the tires that are over inflated!

There's properly over-inflated and then there's OVER-inflated..

[WarpSpeed]

Is 51 the max pressure written on the side walls ?

Go with what it says on the web or better still what it says on a plate probably on the door opening.

The petrol is basically the same everywhere, if your car is capable or using a particular fuel it doesn't matter where you buy it.

Over to Trams Am and Warpspeed.

OMG, not Tran Am with his Nearly Famous Pressure Gauge . .

BTW, you can add me to Transam... i also have now a pressure gauge (to check I am not underinflated!).

Always have my own pressure gauge..

[Ace of Pop]

Check when COLD.?. What defines COLD.? A cold morning in Alaska, or in Thailand. I cant get mine in the Fridge.

[transam]

Is 51 the max pressure written on the side walls ?

Go with what it says on the web or better still what it says on a plate probably on the door opening.

The petrol is basically the same everywhere, if your car is capable or using a particular fuel it doesn't matter where you buy it.

Over to Trams Am and Warpspeed.

OMG, not Tran Am with his Nearly Famous Pressure Gauge . .

BTW, you can add me to Transam... i also have now a pressure gauge (to check I am not underinflated!).

Yes I am lurking here ,

OP, think it's all been said. . Your 51psi is max pressure that tyre can handle IF a particular ride requires it, yours does not. Open the drivers door and somewhere there is a sticker with your rides correct pressures. Test pressure ''cold'', which means before you drive the ride as the air inside heats up in use increasing the pressure a little.

Do not remove the wheels and put in the fridge. .

[sms747]

Thanks for the many helpful replies, never did get a manual even though the dealer swore they posted one!

[Kwasaki]

Thanks for the many helpful replies, never did get a manual even though the dealer swore they posted one!

E91 ??

[BSJ]

Check when COLD.?. What defines COLD.? A cold morning in Alaska, or in Thailand. I cant get mine in the Fridge.

The simple answer is:

1/ Atmospheric pressure is the force per unit area exerted on a surface by the weight of air above that surface in the atmosphere of earth (or that of another planet). In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point. On a given plane, low-pressure areas have less atmospheric mass above their location, whereas high-pressure areas have more atmospheric mass above their location. Likewise, as elevation increases, there is less overlying atmospheric mass, so that atmospheric pressure decreases with increasing elevation. On average, a column of air one square centimeter in cross-section, measured from sea level to the top of the atmosphere, has a mass of about 1.03 kg and weight of about 10.1 N (2.28 lb_f) (A column one square inch in cross-section would have a weight of about 14.7 lbs, or about 65.4 N). Over the area of your body, there is about 1,000 kg of air; this is approximately the same as having a small car press down on you.

2/ Your tires support the weight of your vehicle, right? Well they don't! It's the air pressure inside them that actually supports the weight. Maintaining sufficient air pressure is required if your tires are to provide all of the handling, traction and durability of which they are capable.

However, you can't set tire pressure...and then forget about it! Tire pressure has to be checked periodically to assure that the influence of time, changes in ambient temperatures or a small tread puncture have not caused it to change.

The tire pressure recommended in your vehicle's owner's manual or tire information placard is the vehicle's recommended cold tire inflation pressure. This means that it should be checked in the morning before you drive more than a few miles, or before rising ambient temperatures or the sun's radiant heat affects it.

Since air is a gas, it expands when heated and contracts when cooled. In most parts of North America, this makes fall and early winter months the most critical times to check inflation pressures...days are getting shorter...ambient temperatures are getting colder...and your tires' inflation pressure is going down!

The rule of thumb is for every 10° Fahrenheit change in air temperature, your tire's inflation pressure will change by about 1 psi (up with higher temperatures and down with lower).

In most parts of North America, the difference between average summer and winter temperatures is about -50° Fahrenheit...which results in a potential loss of about 5 psi as winter's temperatures set in. And a 5 psi loss is enough to sacrifice handling, traction, and durability!

Additionally, the difference between cold nighttime temperatures and hot daytime temperatures in most parts of the country is about 20° Fahrenheit. This means that after setting tire pressures first thing in the morning, the vehicle's tire pressures will be almost 2 psi higher when measured in the afternoon (if the vehicle was parked in the shade). While that is expected, the problem is when you set your vehicle's tire pressures in the heat of the day, their cold pressures will probably be 2 psi low the following morning.

And finally, if the vehicle is parked in the sun, the sun's radiant heat will artificially and temporarily increase tire pressures.

We put some of these theories to the test at the Tire Rack. First, we mounted two tires on wheels. We let them sit overnight to equalize and stabilize their temperatures and pressures. The following morning we set them both to 35 psi. One tire and wheel was placed in the shade while the other was placed directly in the sun. We then monitored the ambient temperatures, tire temperatures and tire pressures through the day. As the day's temperatures went from 67° to 85° Fahrenheit, the tire that was kept in the shade went from our starting pressure of 35 psi to a high of 36.5 psi. The tire that was placed in the sun and subject to the increase in ambient temperature plus the sun's radiant heat went from our starting pressure of 35 psi to a high of 40 psi. In both cases, if we had set our tire pressures in the afternoon under the conditions of our evaluation, they would have been between 2 and 5 psi low the following morning.

Next we evaluated the effects of heat generated by the tire's flexing during use. We tried to eliminate the variable conditions we might encounter on the road by conducting this test using our "competition tire heat cycling service" that rolls the tires under load against the machine's rollers to simulate real world driving. We monitored the changes in tire pressure in 5-minute intervals. The test tires were inflated to 15 psi, 20 psi, 25 psi and 30 psi. Running them all under the same load, the air pressure in all of the tires went up about 1 psi during every 5 minutes of use for the first 20 minutes of operation. Then the air pressures stabilized, typically gaining no more than 1 psi of additional pressure during the next 20 minutes. This means that even a short drive to inflate your tires will result in tires that will probably be under-inflated by a few psi the following morning.

Add all of these together, and you can understand why the conditions in which you set your vehicle's tire pressures are almost as important as the fact that you do set it.

It's important to remember that your vehicle's recommended tire pressure is its cold tire inflation pressure. It should be checked in the morning before you drive more than a few miles, or before rising ambient temperatures or the sun's radiant heat affects it.

And by the way, if you live in the North and park in an attached or heated garage you will lose pressure when you leave its warmth and venture into the real world outside during winter. Add 1 psi cold pressure tire pressure to compensate for each 10° Fahrenheit temperature difference between the temperature in the garage and outside.

3/ NOTE! Tyre pressure must always be measured from cold tyres.

Temperature has a significant impact on tyre pressurisation. The temperature in a warm garage can be up to 30 ˚C higher than outside. If the tyre pressure is measured inside, it will be too low for outside temperatures.

Example: The temperature in the garage is +20 ˚C, while the outside temperature is -10˚ C à If the pressure is adjusted in the garage, the pressure added to the tyres must be 30 kPa (0.3 bar) higher than the recommended value to ensure a correct pressure level outside.

The impact of temperature on the pressure of passenger car tyres is approx. 10 kPa (0.1 bar) / 10 ˚C.

In addition to correct tyre pressure, drivers should also ensure that uni-directional tyres are correctly installed on the car. The arrow on the sidewall indicates the rolling direction.

To prolong the lifetime of the tyres, front and rear tyres can be changed from one axle to another every 5,000–10,000 kilometres.

As a result, the tyres will wear evenly and show smaller differences in wear.

[WarpSpeed]

Check when COLD.?. What defines COLD.? A cold morning in Alaska, or in Thailand. I cant get mine in the Fridge.

The simple answer is:

1/ Atmospheric pressure is the force per unit area exerted on a surface by the weight of air above that surface in the atmosphere of earth (or that of another planet). In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point. On a given plane, low-pressure areas have less atmospheric mass above their location, whereas high-pressure areas have more atmospheric mass above their location. Likewise, as elevation increases, there is less overlying atmospheric mass, so that atmospheric pressure decreases with increasing elevation. On average, a column of air one square centimeter in cross-section, measured from sea level to the top of the atmosphere, has a mass of about 1.03 kg and weight of about 10.1 N (2.28 lb_f) (A column one square inch in cross-section would have a weight of about 14.7 lbs, or about 65.4 N). Over the area of your body, there is about 1,000 kg of air; this is approximately the same as having a small car press down on you.

2/ Your tires support the weight of your vehicle, right? Well they don't! It's the air pressure inside them that actually supports the weight. Maintaining sufficient air pressure is required if your tires are to provide all of the handling, traction and durability of which they are capable.

However, you can't set tire pressure...and then forget about it! Tire pressure has to be checked periodically to assure that the influence of time, changes in ambient temperatures or a small tread puncture have not caused it to change.

The tire pressure recommended in your vehicle's owner's manual or tire information placard is the vehicle's recommended cold tire inflation pressure. This means that it should be checked in the morning before you drive more than a few miles, or before rising ambient temperatures or the sun's radiant heat affects it.

Since air is a gas, it expands when heated and contracts when cooled. In most parts of North America, this makes fall and early winter months the most critical times to check inflation pressures...days are getting shorter...ambient temperatures are getting colder...and your tires' inflation pressure is going down!

The rule of thumb is for every 10° Fahrenheit change in air temperature, your tire's inflation pressure will change by about 1 psi (up with higher temperatures and down with lower).

In most parts of North America, the difference between average summer and winter temperatures is about -50° Fahrenheit...which results in a potential loss of about 5 psi as winter's temperatures set in. And a 5 psi loss is enough to sacrifice handling, traction, and durability!

Additionally, the difference between cold nighttime temperatures and hot daytime temperatures in most parts of the country is about 20° Fahrenheit. This means that after setting tire pressures first thing in the morning, the vehicle's tire pressures will be almost 2 psi higher when measured in the afternoon (if the vehicle was parked in the shade). While that is expected, the problem is when you set your vehicle's tire pressures in the heat of the day, their cold pressures will probably be 2 psi low the following morning.

And finally, if the vehicle is parked in the sun, the sun's radiant heat will artificially and temporarily increase tire pressures.

We put some of these theories to the test at the Tire Rack. First, we mounted two tires on wheels. We let them sit overnight to equalize and stabilize their temperatures and pressures. The following morning we set them both to 35 psi. One tire and wheel was placed in the shade while the other was placed directly in the sun. We then monitored the ambient temperatures, tire temperatures and tire pressures through the day. As the day's temperatures went from 67° to 85° Fahrenheit, the tire that was kept in the shade went from our starting pressure of 35 psi to a high of 36.5 psi. The tire that was placed in the sun and subject to the increase in ambient temperature plus the sun's radiant heat went from our starting pressure of 35 psi to a high of 40 psi. In both cases, if we had set our tire pressures in the afternoon under the conditions of our evaluation, they would have been between 2 and 5 psi low the following morning.

Next we evaluated the effects of heat generated by the tire's flexing during use. We tried to eliminate the variable conditions we might encounter on the road by conducting this test using our "competition tire heat cycling service" that rolls the tires under load against the machine's rollers to simulate real world driving. We monitored the changes in tire pressure in 5-minute intervals. The test tires were inflated to 15 psi, 20 psi, 25 psi and 30 psi. Running them all under the same load, the air pressure in all of the tires went up about 1 psi during every 5 minutes of use for the first 20 minutes of operation. Then the air pressures stabilized, typically gaining no more than 1 psi of additional pressure during the next 20 minutes. This means that even a short drive to inflate your tires will result in tires that will probably be under-inflated by a few psi the following morning.

Add all of these together, and you can understand why the conditions in which you set your vehicle's tire pressures are almost as important as the fact that you do set it.

It's important to remember that your vehicle's recommended tire pressure is its cold tire inflation pressure. It should be checked in the morning before you drive more than a few miles, or before rising ambient temperatures or the sun's radiant heat affects it.

And by the way, if you live in the North and park in an attached or heated garage you will lose pressure when you leave its warmth and venture into the real world outside during winter. Add 1 psi cold pressure tire pressure to compensate for each 10° Fahrenheit temperature difference between the temperature in the garage and outside.

3/ NOTE! Tyre pressure must always be measured from cold tyres.

Temperature has a significant impact on tyre pressurisation. The temperature in a warm garage can be up to 30 ˚C higher than outside. If the tyre pressure is measured inside, it will be too low for outside temperatures.

Example: The temperature in the garage is +20 ˚C, while the outside temperature is -10˚ C à If the pressure is adjusted in the garage, the pressure added to the tyres must be 30 kPa (0.3 bar) higher than the recommended value to ensure a correct pressure level outside.

The impact of temperature on the pressure of passenger car tyres is approx. 10 kPa (0.1 bar) / 10 ˚C.

In addition to correct tyre pressure, drivers should also ensure that uni-directional tyres are correctly installed on the car. The arrow on the sidewall indicates the rolling direction.

To prolong the lifetime of the tyres, front and rear tyres can be changed from one axle to another every 5,000–10,000 kilometres.

As a result, the tyres will wear evenly and show smaller differences in wear.

Yes, simple answer..

[Kwasaki]

Check when COLD.?. What defines COLD.? A cold morning in Alaska, or in Thailand. I cant get mine in the Fridge.

The simple answer is:

1/ Atmospheric pressure is the force per unit area exerted on a surface by the weight of air As a result, the tyres will wear evenly and show smaller differences in wear.

Yes, simple answer..

Does that apply when you use nitrogen though.?

Think I need a beer.

Edited June 23, 2013 by Kwasaki

[stevenl]

To prolong the lifetime of the tyres, front and rear tyres can be changed from one axle to another every 5,000–10,000 kilometres.

As a result, the tyres will wear evenly and show smaller differences in wear.

Is the old advice 'move the tires diagonally every 10,000 kilometers still valid? (provided no 1-direction tires of course)

[IMHO]

To prolong the lifetime of the tyres, front and rear tyres can be changed from one axle to another every 5,000–10,000 kilometres.

As a result, the tyres will wear evenly and show smaller differences in wear.

Is the old advice 'move the tires diagonally every 10,000 kilometers still valid? (provided no 1-direction tires of course)

AFAIK, no car or tire manufacturer recommends the old 'X" rotation regime anymore, nor do they recommend including the spare in the rotation. All simply recommend swapping front <--> rear, without changing sides.

[Pib]

Below is a nice Tire Maintenance, Safety, and Warranty Manual from Bridgestone which gives a lot of general information on tires such as tire inflation, rotation, ratings, how to read the codes on the tire, etc. Really an excellent 42 page booklet written in layman's language with lots of pictures....could be one of those "keepers"...I sure know I have a copy saved on my "puter because I liked it so much.

BSFS1.pdf

[sms747]

Never would have thought there was so much just about pumping up tyres! Interesting

[WarpSpeed]

I suspect may be you did ...

[sms747]

No I don't even know how to pump them up, bloke at the LPG station did it for 10 baht

[transam]

No I don't even know how to pump them up, bloke at the LPG station did it for 10 baht

To about 50psi no doubt.