A sometimes close examination of cars, drivers and roads : Q
Question: I have driven sports cars most of my life. I like the handling and the fact that I can control the car. I have recently become one of the many who drive a sport-utility vehicle. I arrived at this with two ideas in mind:
1. We usually drive family and friends when we go out, and it is easier to park one car than four.
2. We do take the occasional road trip and like the comfort of not having to worry too much about weather.
I like driving the SUV except for the fact that it does not handle the way I would like it to. I realize that it is a taller, longer and heavier vehicle, but it should have some handling. While turning, I experience a great deal of body roll. I also experience drifting while in a long curve and find myself having to work the wheel a little harder than I expect. The vehicle does have factory sway bars, and the shocks are in good shape. Is there any thing that you can recommend?
J.M., Covina
Answer: There are a number of things to suggest, but you might not be happy with the results. Few improvements in suspension performance come without some kind of ride penalty.
Aftermarket sway bars that are stiffer would reduce body roll, as would harder sway-bar bushings. The latter might make the ride noticeably harsher; the former probably won’t have much noticeable effect unless the bars are a lot bigger in diameter.
If off-road ground clearance isn’t important, you could investigate aftermarket springs that lower the vehicle. The lower center of gravity would help some. Stiffer springs won’t have much effect on body roll, but the suspension will handle bumpy roads better and be less likely to drift in sweeping corners.
The same can be said about aftermarket shocks, and a good adjustable shock coupled with stiffer sway bars might be the best approach from the standpoint of increased performance without a severe ride penalty.
More About Octane
Q: My 1962 E-Type Jaguar requires minimum 100-octane fuel. Is there any place in Orange County where one can buy 100-octane gasoline? I have tried the supermarket “octane boosters,” but they are expensive and don’t seem to be effective. Do you have an opinion about these products?
G.R., via the Internet
A: I can’t say that octane boosters are a substitute for higher-octane fuel, nor have I seen any tests to back up manufacturers’ claims. Results of a recent test show that it’s quite expensive to boost octane using additives. And, depending on what chemicals are used to boost octane, the additive could damage rubber bushings and gaskets in the carbs.
As for your E-Type, if it’s normally aspirated and properly tuned, we can’t see a need for 100-octane fuel.
According to John Sethian, technical chairman of the Nation’s Capital Jaguar Owners club, the official Jaguar manual calls for 98 octane fuel based on the research method. That equates, Sethian says, to about 93-94 pump octane. While premium gas in California is mostly 92 pump octane, you should be able to use this fuel without knocking, by retarding the ignition timing slightly. He doesn’t recommend using aviation fuel.
Take care, however, to test your new ignition timing when it isn’t 100 degrees out. If your engine still knocks, you could have carbon buildup or another mechanical problem that affects timing.
*
Q: Could someone please explain the difference between the octane levels? My sister-in-law has a Corvette and claims it runs better on the lowest-octane gas. I have a ’68 Mustang and like the higher levels. Also, why in the world is gasoline priced with 9/10ths after the large number? Why not 7/10ths or 3/10ths?
C.M., Northridge
A: Basically, octane describes motor fuel’s resistance to detonation. It’s quite conceivable that your sister-in-law’s Corvette runs fine on regular gas depending on what year Vette she has. The ’68 Mustang’s need for premium isn’t too surprising offhand, given its age, but if Ford says it should run on regular, the need for premium could mean that something is out of adjustment or that you have a more serious problem, such as carbon buildup.
As for pricing gasoline at $1.349 instead of $1.343 or $1.347, I always wondered why it wasn’t simply priced at $1.35. But a very informal poll of two colleagues suggests that it’s a leftover marketing technique--gasoline priced at $1.349 a gallon sounds cheaper than gas priced at $1.35.
If you read last month’s Under the Hood about octane and it wasn’t enough, check out the gasoline FAQ on the Web at https://www.cs.ruu.nl/wais/html/na-dir/autos/gasoline-faq/.html. This behemoth contains details that delve well into the scientific aspects of motor fuel.
*
Q: Since the appearance of the first Highway 1, I drove into the Rocky Mountain area and discovered that regular gasoline is 85 octane. The middle grade is 87 octane. My car normally uses 87 and, to play it safe, that is what I filled up with. I think the high altitude is a factor in 85 octane. Would it have been OK to use the lower octane?
M.H., La Palma
A: Octane ratings are lower at higher altitude, but octane requirements are too. Modern engines (read: electronic fuel injection) can compensate for higher altitudes, so octane requirements don’t go down that much. Older engines, however, run better on lower-rated fuels because they can’t adjust as much for differences in air density and pressure.
*
Q: A company has a magnet it claims will improve engine performance and mileage if it is installed on the gas line. Is there any truth to this?
S.W., Camarillo
A: Not that we know of, nor in any way that we can imagine. Spend the money to make sure your spark plug wires and points--if you have points--are in good condition. Are your plugs gapped correctly? Ignition timing set properly? Carburetor--if your car or truck isn’t fuel-injected--in good condition and set properly?
I know I’m answering your question with more questions, but start with the fundamentals. After that, more performance is most easily gained by improving an engine’s ability to breathe, and magnets won’t help you there.
Origin of the Species
Car manufacturers with racing programs never agree on whose machines are the winningest, but one thing they say in unison is that the investment in racing reaps benefits for the cars we all drive.
Like what, you ask?
Well, probably best known and having had a big influence on what’s on roads today is the disc brake.
The modern disc brake--the design in which a caliper straddles the disc and clamps down when you step on the pedal--originated on the track with Jaguar’s C-Type production racer.
The big advantage to more stopping power for something built to go fast?
The C-Type’s drivers could brake much later before entering a turn than competitors using very large drum brakes. The result in 1952 was a victory at the 24 hours of Le Mans. Five years later, disc brakes made their debut on road cars in Jaguar’s MkII, a compact sedan. And four-wheel discs, says Leslie Mark Kendall of the Petersen Automotive Museum, hit the road that year in Jensen’s 541.
While discs have less braking area than drums, they don’t fade from heat and shed water more effectively.
Widespread use in the United States began in the 1960s, according to the Society of Automotive Engineers’ book “The Automobile: A Century of Progress.” The trend here was encouraged, the book says, by stricter federal regulations for stopping distances, competition in the marketplace and the need for cars that go fast to stop fast.
While the technology is more expensive, most would say the advantages far outweigh any cost. If you’re still in doubt, a drive in an older, heavier vehicle with four-wheel drums should be exciting enough to convince you otherwise.
Improvements have come with better brake-pad materials and power-assisted, but anti-lock systems take things to the next level.
ABS’ significant advantage: the ability to steer under heavy braking. The trick for us mere mortals who have anti-lock brakes is forgetting the old-school braking methods and learning new tricks. In a situation with normal brakes that requires a full turn of the wheel to avoid an object (even without locking up), now less steering input will get you around trouble. Too much will send you into the ditch.
Clarification
Four valves per cylinder--Last month Dr. Gear Head missed a shift during his research on multiple valves per cylinder. Although Harry A. Miller built a lot of engines using the technology, he copied it from a 1912 Peugeot Indy car. Apologies to Peugeot for that. Miller, however, was an influential racing-engine builder. The first road car with four valves per cylinder? A 1922 Ballot. Thanks to all who wrote and called, and to Leslie Mark Kendall at the Petersen Automotive Museum.
