Every car enthusiast has questions they think are too silly to ask so they go unanswered. Until now, that is.

10.) Does My Car Really Need The Expensive Gas?


No, you don't need to put the expensive gas in your car, but you probably should. Reader Thoushalthoonthyrallyetyres can explain why.

"The engine has higher compression ratios than cars that use 'regular', and also derives its power through a more advanced ignition timing. The higher the octane rating, the more the engine can advance timing. Running lower octane gas in your car will lower both your power output and gas mileage, enough that it will likely cost you about the same as running 93 in it."

Suggested By: Nicholas Stango, Photo Credit: David Precious

9.) Why Do Turn Signals Blink Faster When They're Burnt Out?


Science! That's Why! For a more detailed explanation, let's turn to Steve Kuhn.

"It's a relay that switches the light on and off. It blinks faster when a bulb is burned out because the voltage load drops. Less load on the circuit = easier for it to do its job = blinks faster."


Suggested By: FlavioShahiki, Photo Credit: Daniel Oines

8.) Can An Engine Run In Reverse?


Reader TrinTDI wondered if an engine can run in reverse since the primary rotation of the starter motor is backwards. A two stroke engine can, but not a four stroke. So if you've got an old Trabant, go try it at home!

Suggested By: TrinTDI, Photo Credit: ilovebutter

7.) What's The Difference Between A Turbocharger And A Supercharger?


Ok so we both know they do more or less the same thing, but what's the difference? Reader isidor3 has the answer.

"Both devices "charge" the air in the intake by compressing it, and so force more air into the cylinders, allowing you to burn more fuel and make more power. The difference is what powers each device. With a supercharger, the compression pump is connected directly to the engine (typically via a belt) This means that you get reliable compression, and you don't have to wait for it to "spin up", since it spins as quickly as the engine does. The downside to this is that if your engine is turning slowly (i.e. at low RPM's) you don't have as much compression, and as such, less power. You don't get maximum power until you reach the highest RPMs (the redline).

In a turbocharger, the compression pump is powered by exhaust gases. Air pressure from the exhaust pushes on a mini-turbine that spins the compressor. This has the advantage of not directly taking power from the engine (it doesn't directly slow down the crankshaft like a supercharger does), but at low RPM's the exhaust doesn't have enough force or pressure to turn the turbine. When the RPM's rise high enough to generate enough pressure on the turbine, the turbine can take a second or two to fully spin up to a speed where it generates significant compression. This second or two of spin up time is known as "turbo lag". However, turbochargers can reach maximum compression at a much earlier point in the RPM range, and so you can have maximum power from a turbo through more of the RPM range than in a supercharger."


Suggested By: Titan-E34, Photo Credit: iqremix

6.) How Do Diesel Engines Work?


I know diesels are different than gas engines, but how are they different? They essentially do the same thing, but instead of using spark plugs to ignite the fuel as in a gasoline engine, diesel uses compression to do it.

Suggested By: td99, Photo Credit: gavin rice

5.) How Do Pistons Moving In A Jerky Motion Translate Into Smooth Crank Rotation?


Good question McLarry! For the answer lets call upon isidor3 once again.

"Simply put, you put another weight the opposite side of the crankshaft as the piston, so when the piston is moving up, the opposite weight is moving down. Engines also have a flywheel, which is basically a big heavy disk on the end of the crankshaft. It's difficult to accelerate, so any strong force applied to it will only accelerate or decelerate it a little. If that force was only for a short time (a sharp impulse) the flywheel won't change speed. If the force is over a longer time (you pressed on the accelerator and the piston(s) are consistently applying more force) it will speed up (albeit a bit slower than it would if the flywheel wasn't present).

If you have enough cylinders, you can balance the engine so that you don't need extra balancing weights (like in an inline 6 or V12 engine) but they'll still have a flywheel to smooth out any vibrations."


Suggested By: McLarry, Photo Credit: Timitrius

4.) What's The Difference Between Over And Understeer?


If you watch a lot of Top Gear, or any car reviews you'll hear the terms understeer and oversteer thrown around quite a bit. Audistein has a great explanation about what the difference is–check out his comment for a more in depth perspective.

"In the most simple terms possible, oversteer in when the front wheels slip while cornering and oversteer is when the rear wheels slip while cornering."


Suggested By: Enginerrrrrrrrr, Photo Credit: Thomas Forselius

3.) Which Is Better? FWD, RWD, Or AWD?


Unfortunately there is no definitive answer to this question, but each has it's pros and cons. FWD provides good traction in inclement weather because the weight of the engine is on the front wheels and is often cheaper. Generally, FWD cars don't handle well because the front wheels are tasked with all the engines power and the steering.

RWD remedies that by giving the back wheels all the power, leaving the front wheels just for cornering. It's more balanced in terms of handling but not quite as good in low grip conditions.


AWD is best for low grip situations and has some of RWDs good handling characteristics, but is heavy and complex. None is better than the other, they're all just different.

Suggested By: Raphy, Photo Credit: Getty Images

2.) How Do Automatics Work?


The standard answer for this question is "sorcery" but that's not good enough for Jalopnik. Michael Zaite has the best answer.

"You have to separate the Automatic into 3 separate systems. The Torque Converter, the Gear box, and the hydraulic controller.

The gearbox is simply planetary gear sets, the selection is done by hydraulic actuators instead of say hand levers. (there are manual Planetary gearboxes that work with a hand lever, circle track and drag cars use them)

The Torque Converter is a fluid coupling. one side spins transmission fluid around (the engine side), and the other half catches that fluid energy and spins (the transmission side) this replaces the clutch in a manual by simply always having a fluid connection that can be overridden by the brakes.

The Hydraulic controller, now that's the hard part, the transmission has a fluid pump on the input shaft, and either another pump or a pressure regulating governor on the output shaft. The difference of pressures along with spring pressure control valves and flow orifices create simple hydraulic logic circuits. these circuits activate or inactivate the hydraulic actuators that control the planetary gear set. More and more this part is being replaced with computers."


Suggested By: wrxkwndo, Photo Credit: Robert Course-Baker

1.) What's The Difference Between Torque and HP?


This is a very simple question, with a not so simple answer. Reader agjios has one of the best explanations.

"Torque is not dependent on time. Think of trying to unscrew a big bolt. Torque is how many foot-lbs you have to exert to unscrew the bolt. Horsepower is how fast you can do it. Think of a scrawny guy having to use all his strength to barely turn it once every 9 seconds, while the strong man can do it once every 3 seconds. They are both exerting the same amount of torque on the bolt to make it unscrew, but the strong man is generating 3 times more horsepower."


Suggested By: sm70- why not Duesenberg?, Photo Credit: BoostinChick

Welcome back to Answers of the Day - our daily Jalopnik feature where we take the best ten responses from the previous day's Question of the Day and shine it up to show off. It's by you and for you, the Jalopnik readers. Enjoy!


Top Photo Credit: Getty Images

Share This Story

Get our newsletter