AUTOWORLD MAGAZINE #13, 2006

“Trust but check” (Russian proverb)

Today we got used to trust specialists on such matters as car service and tech support. But checking up the pressure in the tires is still being the car owner’s responsibility.

It seems nothing can be easier then just checking of the pressure status in your tires. You need neither big experience nor special technical knowledge to do this operation. What is really necessary here is a precise gauge, a device for pressure measuring. Basing on our own experience we can affirm that not all of the gauges do their job perfectly. Very often gauges can misinform the car owners by showing incorrect values. You can never find a “right” item looking only at his appearance. Although there are no fakes (fake products are being a real evil for today’s car accessories manufacturers), still there are lots of low quality products in the stores. So, should we prefer home-produced products or should we use imported ones?

We can judge about the suitability of any gauge only after tests, comparing the numeric values of the item with the Standard Gauge.  This is what we have decided to do. 10 absolutely different tire gauges were bought in different stores of the city and were represented to “Rostest-Moscow” specialists.

The price variations have frankly surprised us: pressure gauges identical in their purposes and functionality may cost 40 rubles (1.4 USD) or 600 rubles (21 USD), in some fashionable stores they can cost even more. Of course, we have decided to try most affordable gauges costing from 50 to 450 rubles in our test.

“Different sins of different things”

Let me briefly explain the test methods. To control the indexes of our equipment we used a laboratory receiver with high-precision (standard) manometer. The measures were made in different series (5 measures in each) using different pressure values.  We have taken into account the limitations on the items. Filling up the table we decided to work with pressure measures till 4 kgs/cm2 – the limit enough for cars and minibuses.

Two parameters are showing the precision value of the items: First, max. error – the biggest value of difference between the tested gauge and standard gauge  during the series of measures. Second, the difference of indexes – it is a difference between the min and max indexes of the tested gauge during the series. Simply speaking both of these indexes are the same with the indexes in shooting games (accuracy of the shot and grouping of the shot).

Whom to trust, what to buy?

So, what gauges should we prefer? Alas, our expertise has shown that neither price, nor origination, nor appearance counts, when selecting the best item for measuring the pressure in tires. So, if you do not see gauge that you are using now in our test or just planning to buy one, suggest to pass it trough your own test. For the test you will need to visit car tires service and ask them to inflate a tire (better all the tires) to a normative pressure index. Professional instruments that are used in car services are usually rather precise, so you can check your gauge’s accuracy by comparing it’s indexes with the index given (it is suggested to check it for several times). By the way, a very popular way of measuring the pressure in the tire by just touching it by your fingers is only enough for a rough evaluation, so that you can easily be mistaken for 0.5 atm.

MD-214 (black cover)

We failed to trust our home-produced product right after beginning. And it is even not about the bad production itself but about a max inaccuracy of 0.2 atm and difference of indexes of 0.3 atm. Unfortunately the original producer cannot be identified too, so it is only differs by the color of its case.

ÌD-214 (white cover)

The item doesn’t differ much from its analog in the black case by the appearance, but differs much by the precision. So that max inaccuracy is not bigger than 0.1 atm and difference of indexes is only 0.05 atm. The only problem was deflating of the air from tire during the measures. But still the item is all right.

Tire Gauge

This Taiwan item has recommended him not very good. Max inaccuracy was 0.2 atm, although the difference of indexes is not very big. Other disadvantage is that the gauge needle (arrow) pushes its stop point too hard when the item resets, one day the needle (arrow) might break of curve. But by the help of more sophisticated construction the air didn’t come out of the receiver during connection and disconnection.

Piece of Mind PM386
An American brand item commonly can be determined as a satisfactory one. Max inaccuracy as rather acceptable (0.1 ATM), although the difference of showed indexes may could have been lesser (0.15 atm). There is a little airflow out of the receiver during the measures. Also it is not very convenient to read the pressure indexes. It can be hanged on a cloth or a belt, and there is a deflator-button.

Drapper Part #31K

2 items in our test represent the product line of an English company named «Drapper». It is a pen-shaped manometer, which in the beginning we didn’t trust much just like its colleague from Piece of Mind, then he showed nice results: the air won’t come out of the tire, inaccuracy and difference of showed results at the pressure till 1.5 atm are equal to zero. When the pressure is more than 1.5 atm the indexes are 0.1 atm and 0.05 atm respectively, which is ok.

Drapper DTG
Electronic “Drapper” having counting discreetness of 0.05 atm has shown a high accuracy.  It is very comfortable for using, although it would be interesting to check its functionality on a nice cold. From the other side no one would wish to check the pressure in his/her tires at -30°C. Shortly speaking the item is good but expensive.

Practical guy
One of the worst samples of all we’ve had. At pressure value equal to 2 atm this manometer has shown 1.7-1.75 atm. The difference of results (indexes) was ok, but at the moment of connection and disconnection there was air deflating out of the receiver. All this was a pity, because the box actually was all right, all the info was represented in Russian, despite the product has a Chinese origin.

Quality tools TG-8
This item was represented to us as a “professional Italian one” We begun doubting it after a close look at the item. Despite the scale on the gauge was up to 16 bar, the flexible hose could only withstand 10 bar (according to a warning note written on the hose). Inaccuracy and scale factor were 0.2 bar, which is still much for a car. Among other problematic points is a need to push strongly the item downward to the tire during measuring.

BERKUT (!!!“AUTOWORLD” MAGAZINE’S CHOICE!!!!)

BERKUT manometer is not the most expensive one, but the most comfortable, functional and precise (inaccuracy and result’s difference were not more then 0.05). The item has a chuck that can be twisted onto a valve of a tire. There is also such a useful feature as an extra air deflator. The item is sold together with a storage bag.

CarCare TG-8

One more “professional Italian” manometer has really regretted us. To measure the pressure the item should be pushed hard to a tire valve. If the contact is not tight enough the arrow will fall to zero. The hose seem to freeze very fast at cold temperatures. The only plus was a small inaccuracy during measures till 3.5, it is 0.05 bar.

Useful features of the manometers

• Twisting flapper (BERKUT) guarantees precision of the measures and allows avoiding airflow during turning off/on of the manometer.
• Protection case (bag) (BERKUT, MD-214) will protect your manometer from dirt and damage.
• Deflator (or sometimes just a button) will help to deflate extra air.
• Pen-type manometer can be hang on the pocket of your shirt or bag.

Useful features of the manometers

*In the range of measures till 4 atm.