We've been busy. We talked about mental aspects of driving, setting the driver's position to achieve maximal safety before driving, basic emergency handling and about observation and vision ahead. I wish to complete the series by expanding the subject of creating a safe environment before setting out to drive -- this time in aspects of car maintenance.
Car maintenance has a tight connection with effective driving and with safety in particular. Besides tires and dampers that directly effect safety, bad motor oil that causes an engine jam while driving is also not very safe. And again I mention aspects of fuel efficiency, environmentalism, wear, expenses, ride comfort, etc...
As far as oils and fluids are concerned, check them regularly once a week, and replace them as recommended in the car's data sheet. If you are a high-mileage driver or make the car frequently undergo stress (performance driving, heavy-weight towing) or has sensitive mechanics (automatic transmission, heavy vehicles) you should replace oils faster.
Upon replacement, look for quality brands. Synthetic or semi-synthetic lubricants and pre-mixed coolants -- both from a known brand -- will pay you back for the expense quickly!
Mind you, fluids include:
* Motor-oil (and motor-oil filter and the air filter)
* Gearbox lubricant (and filter)
* Power steering oil
* Differential\axle\spindle oil
* Brake fluid
Tires are more important than fluids. Yes, more than your motor oil that keeps the engine from shredding itself. More than the coolant which keeps the motor from burning itself. More than the brake fluid. WHY? Because the engine cannot accelerate you without the tires -- they are the ones that accelerate you. Brakes don't slow down/stop the car -- the tires do.
I have a do-it yourself test: Take two sheets of paper and squeeze them from both sides of a tire under your car (front to-rear of the tire). Eventually, the sheets will meet resistance that will prevent them from drawing closer to one another. The gap left between the two sheets is the ONLY thing that keeps you and the road connected. It's even less than that because road tires have a tread that puts some of the rubber off of the pavement.
This little patch has a lot to do: It has to cramp around, pull you from a stop, accelerate you, slow you down, stop you, keep you at a constant speed, dampen bumps, turn the car, sustain pressure, physical forces, contact and heat, clear water and dirt from the way, hold the car's weight (plus additional load). That's a lot of effort in a day.
Even if you look at one job, the load on the tire is immense. Just by looking at the amount of water a tire has to clear at 60mph, we reach the figure of one gallon of water! I repeat that all these jobs are made simultaneously within the radius of this tiny patch!
To make sure it gives us most grip, we need to make a lot of arrangements regarding tire replacement, placement and inflation. First, tire replacement. Replace tires once a single one of these conditions exists:
1. It appears worn: Dry, cracked, slashed, scrubbed, swallowed, deformed, shallow treaded (less than 3 mm of tread depth).
2. It has done 70,000 km: No matter how good it looks, a tire with this mileage has lost most of it's ability to slow you down or keep your car in a turn.
3. It has "lived" for three years: Look on the tire's sidewall for a four numbers: A week of the year. 3010 -- the 30th week of 2010. 2610 -- the 26th week of 2010 (the age of my tires). A tire at the age of three, even if has not been driven and looks great -- lost about 50% of it's abilities. That's 50% more stopping distance in an emergency and 50% less likelihood of making it out of slippery bends!
Upon replacing tires, replace the whole foursome. None of this "good tires go on the front/rear". The good tires go on...ALL FOUR WHEELS. Period! Buy NEW tires from a known brand. Unknown tire manufacturers make tires that can sometimes be just as bad as your old tire! Also, choose the right tire for the job. Don't use a snow/winter tire in dry seasons and don't use all-season/winter tires in the snow!
So, by now it's simple: Whenever your tires get worn/damaged, or when they do 70,000 km or three years -- you should replace them for a new foursome from a known tire manufacturer. The last detail to look out for is tire inflation. Again, this also makes a HUGH difference and it's highly neglected. Even those who care about tire inflation usually don't have the proper standards (like with the criteria I managed earlier).
My recommended standards are:
- Check tire inflation once every TWO WEEKS (not once a month)
- Check tire pressures when the tire is cold, with a personal air gauge. There are pencil air gauges that are cheap and are highly reliable over time compared to other personal gauges and the public gauge in the pump at the gas station.
- If it takes some considerable driving to get to the gas station, touch the tire's sidewall. If it feels warm, the tire is hot. In that case, the proper air inflation should be 10% above the "cold" air pressure.
- You don't have four tires, you have FIVE. Maintain and inflate the reserve tire too!
- Three normal adults, or some heavy cargo, put extra load on the car. Car manufacturers state different pressures for "loaded" cars. In trips with a loaded car, make sure to check the air pressure and inflate it to the proper pressure for a loaded car!
- In both cases of a loaded car or inflating hot tires, overinflation is by far more preferable than under-inflation. Overinflation gives better grip than under-inflation, less wear and the extra air can be removed manually once the tire is cooled-off or when the car is unloaded.
- Put the tire's air nuzzle caps back on once done. They are important.
Summary on tires:
- Most important, but also most cheap of car parts.
- Upon replacing tires, get a foursome of tires from a known brand.
- Replace tires once they appear worn or once they exceed the mileage of 70,000km or three years of age.
- Minimum tire tread depth: 3 mm (not 1.6 mm!)
- Check tire pressure once every two weeks with your own pencil gauge.
- Consider tire temperature and car load upon inflating tires.
Dampers are a part of the suspension that helps it keep the tires flat against the ground during body roll and over bumps. They are hydraulic instruments that suffer wear. You can test how well they operate when the car is turned-off and parked: Push down hard on one corner of the car and see whether the car oscillates: Does it saw back and forth up and down? Once-twice is acceptable. If it bounces more than that -- the dampers are malfunctioning. Regardless, dampers should be replaced once 90,000km.
A good damper + Good tires + Tire inflation + Fresh brake fluid = reduction of up to 70% in the stopping distance during an emergency!! Good tires and dampers also increase grip in corners by similar rates and improve handling and control. Good tire tread depth and inflation will increase grip on the wet and reduce the chance of hydroplaning significantly. Snow tires will increase grip on snow from virtually no grip, to a manageable amount of grip. Car maintenance saves lives.
But what if...
What if the engine starts boiling or when a tire is punctured? Let's say either of the two occurs in a highway with an open hard shoulder (no protected rest stops) -- should we stop. My answer is simple: NO! Open hard shoulders of highways are EXTREMELY dangerous. Under no circumstances should you stop there, not even if you get a puncture over the tire which is not facing the road.
By slowing down and driving on the shoulder (but not stopping), you can drive fairly nice on a puncture towards a near spot which presents a reasonable place to stop. Engine boil-up also occurs gradually, so there's always time to reach a normal place to stop.
If the engine has shut-down altogether, it's still possible to try and let the car slide in neutral towards a close stopping location, or at least let it slide towards the right shoulder (the left shoulder is prohibited!) and as far away from the road. If this happens, you need to get over the armco. If not possible, stay with "HAZAD" lights on, buckled inside the car and keep the brakes on hard until a tow-truck arrives.
Thanks. I'm trying to post information that will illustrate how important this subject is. The effects are enormous! That's why it's important the be strict with tires in particular. I have one example here.
The video is in my native language of Hebrew, but it is has annotations in English. I have several more examples that I would arrage for to be orginized in one video, which will emphisize the importance of tires.
Joined: Aug 02, 2006
Location: McLean, VA, USA
Sun Feb 06, 2011 1:15 pm
Yep, I totally agree on tires being probably the most important part of your car, safety wise. Cheap tires are a surefire way to disaster. Though the very expensive ones are not necessarily the best. I usually settle for Yokohama Avid, they seem to have great handling properties both wet and dry, and do not cost arm and leg.
• Regular oil changes are very important to keep your engine in a good shape.
• Wash your car regularly, wax it once in a while to keep the car body shiny and free from corrosion.
• Take care of any minor concerns as soon as you can, so it won't cause serious problems and an expensive repair later
• Use only original parts
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