pressure

[norseman]

I always keep a regular check of tyre pressures on any car that I own & never cease to be amazed by the number of owners (especially elderly) who really believe that these checks only need to be made when the car goes in for service.

I use an old Kismet brand pencil gauge that I've had for decades & although it was found to be accurate years ago when Trading Standards were offering free tests on such devices, I don't know if it is still accurate today. In addition to the Kismet I have another more modern 'pencil' & a cordless compressor that has a built in digital readout ... all 3 give different readings on the same tyre !
In this day & age is the digital the most likely to be correct ? TS no longer carry out free checks on gauges & the charge for such a service, last time I looked, was more than the cost of a new item.

 

[Gasguru]

A simple spring in the old fashioned gauge is likely to be far more accurate than the cheap modern sensors IMHO.

 

[ReganAndCarter]

I've got a PCL pencil gauge that has given several decades of reliable service, so that brand seems to be good quality and reliable.

https://www.pclairtechnology.com/tyre-care-tools/tyre-pressure-gauges

Wouldn't rely on the ones at garages that get abused or the cheap ones on foot pumps.

 

[Burnerman]

Typical digital gauges such as these:
https://www.toolstation.com/draper-...MIxIeQ8OTr8AIVmPhRCh19HwCjEAQYBSABEgJ-__D_BwE
are claimed to be accurate within 2% when new - I find them reliable enough.
Traditional pencil gauges are very good too, just keep dust and grit away from them.
A pressure discrepancy of a couple of PSI in a tyre won't be noticeable to the driver but depending on the system may upset the tyre pressure monitoring on your car.
John

 

[Mottie]

The PCL ones I use at work come with a calibration certificate. I treat them with kid gloves and they don’t get chucked about or dropped. I’ve had them at least 10 years and I’ve never had them recalibrated but funnily enough, last week I repaired a puncture for my mate on his wife’s Fiesta. After I had done that, I adjusted his pressures (they were all too high) and he checked them on the dash. The display on the dash gave the actual pressures in bar and they tallied exactly with what my gauge showed.

 

[Harry Bloomfield]

The PCL ones I use at work come with a calibration certificate. I treat them with kid gloves and they don’t get chucked about or dropped. I’ve had them at least 10 years and I’ve never had them recalibrated but funnily enough, last week I repaired a puncture for my mate on his wife’s Fiesta. After I had done that, I adjusted his pressures (they were all too high) and he checked them on the dash. The display on the dash gave the actual pressures in bar and they tallied exactly with what my gauge showed.

I have a compressor in my garage/workshop (lots of tyre to be kept inflated, etc.) and it is piped around the place. I went through a period of buying a few different gauges of various types, I have around 8 scattered around the place, including a PCL digital complete with calibration certificate. I also have an old pencil mechanical type I bought over 50 years ago, digital and etc.. The PCL compares to within 0.2 PSI with my other digitals and as near as I could read them, to the pencil types, including the 50+ year old one. One of the pencil types, was just a free gift given away with a magazine.

Having once been fooled by a multi-meter showing wrong values, I now try to have at least three instruments to use for comparisons. If things seem wrong - If two agree and one doesn't, I accept the values shown by the two.

 

[norseman]

Traditional pencil gauges are very good too, just keep dust and grit away from them.
A pressure discrepancy of a couple of PSI in a tyre won't be noticeable to the driver but depending on the system may upset the tyre pressure monitoring on your car. John

No danger of that John, one is 23 yrs. old & the other 34
Thanks for the advice.

 

[Keithmac]

We have calibrated digital PCL's at work.

I have a nice mechanical dial guage for home, tested against the PCL and it's within 1 psi.

 

[norseman]

Thanks to all for the replies, think HB's advice makes sense.
The digital read out is on a cordless compressor, doubtless of Chinese origin it is nevertheless very handy as one of the cars is parked away from the home. The device has an impressive battery endurance though the weakness of these 12v units is the compressor, but mine is still going strong after 2 years ... not bad for £40.

 

[ericmark]

I know with the Kia tyre pressures are rather important, the front wheels with a front wheel steer vehicle will travel further than rear wheels, so the car monitors wheel speed and if rear wheels travel further than front then it engages all wheel drive, so most worn tyres always need to be on front wheels, if rear tyre pressures are low the car will randomly drop into all wheel drive.

The pump my wife got can be set to auto cut out at correct pressure, I find this is the easy way to ensure all wheels at same pressure.

I know my son with a Jaguar XE with all wheel drive also finds type pressures makes a difference to fuel economy, just 2 lbs/in² too low and fuel use goes up. Think wife's Jaguar XE which is 2 wheel drive, has not used a full tank of fuel in 14 months of lock down, big worry is add blue going off. All I seem to do is move smart charger from one car to next, and just as we could start to drive again, the DVLA is playing silly with my licence, just turned 70 and was on paper with no passport, renewed on line, then got a on line renewal form through post, submitted pictures etc, only to get more requests to prove I am me.

It says once applied if a valid application I can drive, but how do you know if valid until they return the licence? And just to add to it, now the Police seem to think wife has not got a licence, and she sent it to DVLA to get address changed, and we can't get in touch with DVLA to find if either of us can drive.

So at the moment reduced to riding an e-bike.

 

[norseman]

It says once applied if a valid application I can drive, but how do you know if valid until they return the licence? And just to add to it, now the Police seem to think wife has not got a licence, and she sent it to DVLA to get address changed, and we can't get in touch with DVLA to find if either of us can drive.
So at the moment reduced to riding an e-bike.

I went through all this 6 years ago, but without hassle ... things seem to have gone downhill on a handcart.
Feel for you both, hope things get sorted soon. Take care on that 'bike

 

[Mottie]

I know with the Kia tyre pressures are rather important, the front wheels with a front wheel steer vehicle will travel further than rear wheels, so the car monitors wheel speed and if rear wheels travel further than front then it engages all wheel drive, so most worn tyres always need to be on front wheels, if rear tyre pressures are low the car will randomly drop into all wheel drive.

I can’t see that happening. If the front wheels were travelling further than the rear, wouldn’t the tyre pressure monitor system or the ESP throw up errors?

 

[ericmark]

Ackermann system always does this see here been a long time since I passed my motor vehicle technicians certificate part 2 around 1978 but nothing has changed except for one odd car that had rear wheel steering like Honda Prelude and Porsche 911 GT3.[/URL]

 

[Mottie]

Ackermann system always does this see here been a long time since I passed my motor vehicle technicians certificate part 2 around 1978 but nothing has changed except for one odd car that had rear wheel steering like Honda Prelude and Porsche 911 GT3.[/URL]

Same here. I passed mine with distinction also in 1978. I thought you were referring to the front wheels constantly travelling further. The system you refer to is no different to the rear wheels where the outside wheel has to travel further than the inside one on a turning circle. All the Ackerman angle does in that case is to prevent tyre scrub on the front tyres when turning. It’s not to allow the front wheels to travel further than the rears.

Search 'TOOT' (Toe Out On Turns).

 

[Keithmac]

Our car has Intelligent AWD, tyre pressures don't come into it.

The car uses ABS and wheel speed to detect a flat tyre, caught one at 25 psi (we run 35).

There's been massive advances in AWD technology, pre programmed modes etc.

Ours reacts to throttle input, steering angle, yaw and a million other factors to decide what to do with the diff (torque vectoring). Even on bone dry roads it is feeding power to individual wheels for best stability and cornering.

It does shut power to rear wheels when cruising on motorway etc.

Even in last 10 years cars have come on an incredible amount technology wise.