Car Quiz!

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How much do you know about your car – and what’s good (and bad) for it?

Take this quick quiz and see!

* Regular vs. premium gas?

Some cars require premium; others merely recommend it.

Which should you use?

The answer is – either!fuel quiz pic

If your owner’s manual says the engine requires premium fuel, it means is designed to deliver the rated horsepower (and fuel economy) using premium. But you can use regular (and mid-grade) without hurting anything. You may notice a slight dip in fuel economy – but it’s not likely this will be enough to offset the 20-40 cents more per gallon that premium will cost you ($3-$6 more per tank, assuming a 15 gallon fill-up).

As far as horsepower: Yes, your engine  – if it’s a “premium fuel only” engine – will make less than the advertised maximum, as the engine’s computer will alter certain parameters (such as ignition timing) to adjust for the lower octane fuel. But unless you’re doing time 0-60 runs or testing the engine’s maximum output on a dyno – it is not likely you will notice any difference in real-world/everyday driving.

Conversely, if the engine was designed to run regular unleaded – which is lower octane, not lower quality – and you feed it premium (higher octane fuel) all you’re doing is burning up money and wasting fuel, as the engine will deliver lower fuel economy and you’ll be paying 20-40 cents more per gallon.

* Are “high-performance” tires better than standard all-season tires?

The answer is – it depends!sport tire pic

If by better you mean lasts longer, you definitely do not want high-performance tires (often marketed as “sport” or “summer” tires) which wear much faster. Not uncommonly, 50 percent faster than all-season tires. They are also usually noisier, awful in the winter and tend to make the car’s ride noticeably harsher.

On the other hand, if you fit your car with performance tires, it will feel more agile; steering response will be sharper, the car will be able to take corners at higher speeds without losing grip (or the tires squealing) and stopping distances will be reduced.

Which of these attributes you value the most will help you decide which tire type is the one for you.

* Should you let your car “warm up” for a few minutes in the morning before driving off?

The answer is – no!

Well, unless your car was made before about 1985.warm up pic

Cars built since then are all fuel-injected and fuel-injected cars don’t have chokes (as the older, pre-’85 cars with carburetors did) and so are ready to drive as soon as you start them up. Prolonged idling only wastes fuel and actually increases the time it takes for systems such as the heater to begin working.

It’s still good policy to drive gently for the first five minutes or so, though.

While modern engines are pretty much ready to go as soon as you turn the ignition key (or hit the starter button), other driveline components – such as manual transmissions, axles, wheel bearings and so on – will still be grateful to you if you take it easy until they warm up a little.

* Should you run the AC in the winter?

The answer is – yes!AC pic

For two very practical reasons. The first is that by turning the AC on when it’s cold, you will cause lubricant to circulate within the AC system, which will keep internal seals pliable and keep the refrigerant from leaking past those seals. Which will improve the odds that – come next summer – you will not find out that your AC system is blowing nothing but warm air, because all the refrigerant escaped over the winter.

The second reason to turn on the AC is to help dehumidify the interior – specifically, the windshield. If your car has automatic climate control, the AC will do this (come on) automatically but if your car has manual AC it may be necessary to manually push an “AC” button to get things going – so you can see where you’re going.   

* Is oil “just oil”?

The answer is – no!

Never use any oil that doesn’t meet the car manufacturer’s minimum specifications – and is of the correct viscosity (e.g., 5W-30; this information will be listed in your vehicle owner’s manual). oil pic

Use of oil that doesn’t meet the specs can lead to mechanical problems that will not be covered by your car’s warranty. This should put into perspective saving a few bucks on a case of “on sale” oil.

Also: be sure to use only oil filters that meet the manufacturer’s requirements. A below-spec filter can really cause problems – and those problems would also not be covered by the warranty.

Tip: If you have your oil changed by a non-dealer be sure to check that they use the right type of oil and filter (and that it is listed on your paperwork). And be sure to check the dipstick yourself after they are done – and before you drive away. Some quickie-lube places have been known to over or under-fill the crankcase – which can have catastrophic consequences.

* Are drive-through washes safe?

The answer is – usually!car wash pic

While there may still be a few of the old-school car washes left that use brushes to scour the dirt off your car (and with it, the paint) most modern car washes are “brushless” – they use fabric strips that kind of mop the dirt off, very much as you would if you were washing the car by hand. They have the additional advantage of using high-pressure water in great abundance to get most of the heavy dirt off without even touching the finish.

Drive-through washes also usually offer underbody spray – either standard or extra. This is worth doing – and worth paying a little extra for – if you live in a state where road salt (which accelerates rust) is used in the winter time.

It’s a lot easier than trying to do the same thing on your hands and knees with a garden hose!   

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  1. Modern carwashes may usually be safe for your vehicle’s finish. But for some reason, a certain number of them have a tendency to rip mud flaps off your 4×4 truck or SUV. And of course, their disclaimers state that this another in a long list of things for which they will not be responsible. Depending on your vehicle, many carwashes will not damage your mud flaps. But it can be expensive to learn which is which by trial and error.

  2. I think a mpg comparison is a good way to determine if you should run premium fuel or not. My supercharged 3.8L Regal will get an extra 2-3 mpg on premium and when scanning for knock retard (when the pcm pulls timing), premium gas eliminates it under most conditions. On the stock tune it maxed out at 26.5 mpg highway with as much as 8 degrees of KR, with the new tune (and some exhaust modification) I see 28.5 driving at 80 mph and just a blip of KR on the 1-2 shift at WOT. It’s also worth noting that the highest counts of KR (stock tune) would occur when loafing along at 45-50 mph in overdrive with a load on the motor (uphill/headwind/etc..), not when hammering the gas. I have heard a lot of stories of chipped pistons in these cars from people not mindful of KR conditions, I’m not sure but I suspect there is a limit to how much timing the pcm can pull and if you are slightly out of tune (think vacuum leak/plugged fuel filter/etc..) you can damage the motor. I wouldn’t run less than premium in that car without removing the supercharger belt or unplugging the boost bypass (limits boost to about 4 p.s.i.).
    On the flipside is my iron headed LT-1 Roadmaster. It has 10:1 static compression with a tiny little cam in it (high cylinder pressure) but sees no difference between 87 and 93 octane fuel. An old school motor built like that would probably knock itself to death on 87 octane unless the timing is severly retarded.

    • In my experience, the older stuff (I’m talking pre-1980s) with iron heads and (of course) no knock sensors or capacity to adjust timing on the fly is really sensitive to octane. Even my Trans-Am, which has low (by modern standards) compression, can’t deal with 87 octane without me dialing back the timing by several degrees (manually, of course). But I gather (from friends who’ve done it) that you can run fairly high CR in these engines using the aftermarket aluminum heads, because they run so much cooler than the cast iron stockers.

      • eric, did you notice that mod on something here recently with emthanol/water mix that would allow you to use much more timing? I can’t remember but seems like it was something you tested.

        When I saw that I went to the barn and found my old reservoir(didn’t get it out from under the Elco though to see the brand)for the methanol/water mix that allowed me to run more initial and total timing. It was easily felt at any speed and that was barely electronics that controlled it. Iron head and 10/a compression with unleaded and you could keep your foot into it hard all day in west Tx heat.

        • Hi Eight,

          Yeah on the methanol injection. But – for now – I’m leaving my Trans Am alone. I’m broke (and probably going to be divorced soon) so the last thing on my agenda is ol’ Chief Plenty Horses. I’m just hoping I can avoid losing him (and the bikes).

          • eric, I forgot to mention that was back when there was still 98 octane premium around too.

            I’m so well-versed in being broke the only difference a divorce would make is nobody to shoot at me. Well, that’s not entirely true. I never knew you could be a lead magnet till the late 70’s. I’d rather be a lead magnate…..and I’m trying. I still dispose of old batteries for free……and 748 and 780 powder. Donations accepted.

            I hope the best for you and yours…..and that your wife is a lousy shot like mine.

          • Sorry to hear you’re facing a possible divorce. That’s not a pleasant experience at all.

            If you are losing ties back east, come west my friend.

              • I’m hoping with you. Tough for women to understand passions the same way we do.

                I’d say libertarian anarchists have the hardest time getting women to understand and just be okay with our passions. Women tend to need you to appreciate theirs, while men don’t care so much if they reciprocate or not.

                • Thanks, Ancap…

                  There’s been lots of financial pressure, too – alluded to here previously. It’s part of what’s making me consider going back on the reservation. Many of life’s problems are lessened when money pressures are relieved….

                  • Eric – thinking of you at this difficult and hoping you and your wife can work things out. As for divorce, been there, done that, couldn’t afford a T-shirt.

                  • eric, you can be old and broke like me. When I started trucking it wasn’t as though I had no boss since brokers, customers and all the revenooers of one sort or another are standing there hands out or getting their due off the top. Still, when I’d do something else and have to associate with people I had virtually nothing in common with, I’d be miserable. When you have values and standards it never gets easier although I hope you have found a formula that eventually will sustain you and not have to rub elbows with people you simply have nothing in common with.

                    I once thought that was a common thing and it probably is. I had a friend last week quit his job and start running a truck he was considering having me run for him. The patch is full of people trying to do their own thing, get a bit more control of their destiny.

                    I was speaking with some employees at the Verizon store a couple weeks back, one a closet libertarian(couldn’t say much at work). I spoke of making twice as much money as I did in ’74 when money is worth a sixth of what it was back then. One young woman said she’d gladly take my pay from back then so I know she wasn’t making crap.

                    Don’t worry though, plenty of clovers willing to keep their betters butts clean and smile doing it.


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