people often do bad things to their cars without realizing
it, or understanding what the possible consequences could be. So,
which is worse?
pressure in your tires will result in a harsher ride as well
as faster (and uneven) tread wear. Youll be paying
more for tires more often. Handling and braking performance
may be negatively affected, too.
On the other
hand, under-inflated tires are more insidious because people often
dont know or notice that their tires are low
on air mainly as a result of benign neglect and because tires,
air valves (and wheels, if theyre aluminum) commonly
leak air. A tire usually has to be really low on air
maybe even close to flat before its visually obvious.
Meanwhile, youre driving around on a tire (or tires) 5, 10
or even 20 psi below the recommended pressure which can lead
to weird handling/poor braking, even a sudden failure due to the
heat build-up. The classic case being the Ford Explorer/Firestone
tire debacle of the late 90s. People were driving at high
speeds, on hot days on under-inflated tires. Which failed
catastrophically and suddenly leading to numerous
wrecks and deaths.
Check the air pressure in your tires with a gauge
not just by looking at them at least every two weeks. Be
sure theyre all filled to the specified pressure neither
too much nor too little.
quart in the crankcase? Or down a quart?
take their cars to a quick lube place for oil changes. These places
typically use a gun to shoot new oil into the engine as opposed
to pouring it in a quart at a time. Its not uncommon for the
result of this to be too much or too little oil in
the engine. Whats the difference?
Running a quart
low is less potentially damaging than running a quart over. Reason?
If theres more oil in the crankcase than the engine was designed
to hold, that oil has to go somewhere. What happens is it
gets turned into a foamy froth as the engines reciprocating
parts churn it around. This foamy frothy oil is less able to lubricate
vital parts -which can lead to a catastrophic engine failure. Or,
the excess oil might get sucked into the combustion chambers, where
it gets burned partially with the resultant oily residue
ruining expensive 02 sensors and catalytic converters.
On the other
hand, most engines will not be harmed if run a quart or so low for
a little while. Since all internal combustion engines use a certain
amount of oil during normal operation, its expected the level
in the crankcase will occasionally be less than full.
The engineers who designed the engine designed in an extra margin
of total oil capacity for just this reason.
The key thing
is to be sure to check the oil level immediately after every
oil change, if you have your oil changed by someone else
and at least every couple of weeks thereafter.
right away or warm it up a little first?
One of the
biggest differences between old cars those built
before the widespread adoption of electronic fuel injection and
computer controls in the mid-late 1980s and modern
cars (everything made after that time) is the warm-up protocol.
without computers and with carburetors -needed more cold
start hand-holding. It often took a couple of minutes for the choke
to turn itself off and the engine to settle into a comfortable (and
stall-free) idle. With modern cars, warm-up happens much faster.
Most owners manuals say its fine to drive away normally
immediately after start-up.
[send him mail] is an automotive
columnist and author of Automotive
Atrocities and Road Hogs (2011). Visit his
© 2012 Eric Peters
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