Why Do Gas Pumps Have Octane Ratings?
May 25, 2014 / Sara Davis / Keep My Car Running Smoothly
Whenever we go shopping for just about anything, we’re faced with a multitude of choices.
At the mall, there is an endless array of brands to choose from.
At the grocery store, there are gourmet items and generic brands.
Even at the gas pump we face a choice – premium unleaded versus regular unleaded. But at the gas station, many of us don’t know the difference or which gas is best for our car.
Here’s all you need to know about each type of gas.
Regular Unleaded (87 or 89 Octane)
This is the standard and cheapest option at the pump.
And there’s nothing wrong with it – most manufacturers recommend that people put regular unleaded in their cars. Check your vehicle’s owner’s manual to see what your car manufacturer recommends and simply go with that.
If regular unleaded is all your car needs, don’t spend extra on higher octane gas. Your vehicle likely will not see any improvement in performance or fuel economy - it's not a "treat" for your vehicle!
Premium Unleaded (91+ octane)
This type of fuel has a higher octane level, typically between 91 and 93.
For example, regular unleaded might be around 87 octane while premium would be 90 or 91. Keep in mind that each gas station is different, so make sure to pay attention to the octane rating on the pump. Some cars require high octane fuel, such as performance vehicles, motorcycles or some luxury cars.
This is a requirement due to the way the engine was designed and tuned, and it could harm the engine by putting anything lower than 90 octane. Many people think that because sports car require 91, their Honda Civic should get the good stuff too, when that simply isn't the case.
You'll simply be wasting your money.
Once again, it all goes back to what is recommended for your engine by the vehicle manufacturer.
Which Gas Station Is The Best?
As we mentioned earlier, not all gas stations serve the same gas.
The reality is that the oil is essentially the same, it's the additives that each company adds, or doesn't add, that makes the difference.
Each has their own special blend and no one can say for sure which one is the best, although its regarded that Shell and Chevron are the leaders (and also typically the most expensive). Always check the labels at the station or ask a fuel attendant for details if you’re curious about their fuel.
Take note how your vehicle performs after a fill up. If you hear your engine "pinging" or have noticeably less fuel economy, it could be that your engine didn't agree with the fuel your fed it.
When it comes to gasoline, there are many old myths that consumers can get trapped into.
Many people believe that topping off the tank is good for the engine. It isn't. When it's full, it's full. Topping it off is likely just wasting fuel, costing you more money and can allow fuel to spill out of the tank and onto your vehicle. There's a reason why fuel automatically stops pumping!
Another myth is that keeping your tank half full will prevent evaporation and save gas. However, newer cars all have vapors in the tank and very little is lost through evaporation. Most people would agree, however, that keeping your tank above a quarter tank full is recommended as it ensures your fuel pump has enough gas to deliver to the engine, and you won't be caught stranded.
Many people also believe that cruise control saves gas, but this isn’t always true either. This may be the case on flat surfaces, but cruise control can cause over-acceleration on an incline, increasing fuel consumption.
Lastly, if your vehicle takes unleaded gas, as most passenger vehicles do these days, don't ever use diesel. It can (and will likely) cause irreparable damage to your engine, unless, of course you drive a vehicle with a diesel engine. Stick to regular gas!
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