The typical gas station pump offers three to four different fuel options, making it confusing. Which type of gas should you use in your car? Odds are your vehicle manufacturer specifies which type in your operating manual, but if high gas prices are causing an issue - you can almost always use regular unleaded without risk of engine issues or damage.
It’s always better to use the lowest-grade unleaded fuel than to run out of gas on a road or highway, requiring roadside assistance.
Just as there are different types of oil, all designed for various engines, climates, and driving conditions, there are also multiple types of fuel. Here is a more detailed look at your gas options, their differences, and what they mean for your car’s engine and performance.
The large majority of American drivers use regular unleaded (octane level 87) because it is the most affordable gas for vehicles on the market. This is just fine and will not damage your vehicle (excluding diesel engines, which are a different story). The octane level does not affect fuel efficiency or power. Rather, it makes a difference during engine ignition in older model cars.
Fossil-fuel-powered cars use a combination of compressed air and fuel, which is ignited via a spark. The lower the octane, the earlier the fuel-air mixture ignites, called “preignition.” In the old days, preignition was audible and sounded a bit like the gentle knocking sound a coffee percolator makes as it gets going. Higher-octane fuels are more resistant to the preignition reaction.
That said, modern technology and engineering innovation mean preignition is hardly a problem anymore. However, you may notice that people who drive vintage and classic cars are more likely to use higher-octane fuel since their vehicles were made prior to the preignition-mitigation features.
So, again, if your vehicle manufacturer recommends regular unleaded (87), that’s what you should use. Spending extra is doing nothing to benefit your car, and it’s only draining your bank account.
You may feel like you’re giving your car a treat by filling it up with premium-grade fuel. In most cases, you’re just wasting money at the pump. Despite what the fuel industries advertise, very few vehicles “need” premium-grade fuel to run efficiently or more smoothly. Contrary to what you’ve heard, high-octane premium grade fuel does not:
Unless you’re a race car driver, even a high-performance car will do just fine on standard fuel. While we always advocate honoring the manufacturer’s recommendations, no damage can occur to your engine as a result of choosing a lower-grade fuel for a while. Those days are a thing of the past.
Your mechanic is most likely to recommend a premium grade fuel if:
To reiterate, if your vehicle manufacturer or the mechanic says higher-octane fuel is recommended, you’re free to use regular octane (87) without any worries. If the vehicle manufacturer or after-market parts manufacturers say high-octane (91 or 93) is required, you should honor that advice and use that type of gas.
If your engine is diesel, you must use diesel fuel. The ignition system in diesel engines is designed using a different process. If you accidentally use diesel instead of regular fuel - or vice versa - the car or truck won’t run, and you’ll be facing a steep repair bill from your mechanic.
Diesel fuel is clearly marked, and Bay Area gas pumps use a green nozzle to differentiate diesel pumps from unleaded fuel to further minimize confusion.
Ethanol is a clean-burning fuel, most often produced as a byproduct of corn and soy. In the case of E85 fuel, 85% of the fuel is from ethanol, and the remaining 15% is gasoline. It is also called a “flex fuel,” and more and more auto manufacturers are producing “Flex Fuel” vehicles that can run on flex fuel, minimizing emissions.
Flex Fuel vehicles can use regular octane gasoline if flex fuel (E85) is unavailable. Regular vehicles can also use flex fuel, but you’ll notice a difference in gas mileage since flex fuels are less efficient - counterbalanced by more affordable prices and reduced harmful emissions.
The most important thing to remember about fuel, regardless of which type of gas you use, is to keep your tank above the half-full line. Keeping a “tank is half-full” perspective on fuel minimizes your risk of running out of fuel on a roadway. And, as those of us in the Bay Area know all too well, a full tank is ready for any emergency evacuation that may be required due to fire or other natural disasters.
Did your gas tank run empty sooner than planned? Contact J&T Towing, at (707) 356-4613, and one of our friendly roadside assistance technicians will bring you enough gas to get you to the next service station. Drive safe
