There is a lot of debate when it comes to fuel choices. They say that premium goes a long way for taking care of your car. They also say that premium fuel lasts longer than regular fuels. There are also others still that say that you get more power out of premium than regular.
All of these claims are somewhat true, but it would depend heavily on the car that you drive. There are premium gasoline and diesel products out in the market that cost a few pesos over a liter of the standard stuff, but is it worth paying if it just works anyway?
For this comparison, we’re including standard gasoline and diesel fuels. For all gasoline in the Philippines, you get what is called a Research Octane Number (RON), and the higher this number goes, in most cases, the more expensive the fuel becomes. The lowest RON that you can get in the country is 91 RON. Other manufacturers advertise their standard gasoline product with up to 93 or more RON but sell it for the same price as regular. Standard gas will be those products with 93 RON and under for the Philippine market.
Diesel, on the other hand, doesn’t use RON, instead, it is the Cetane rating or Cetane Number (CN) that is indicative of a diesel fuel’s premium-ness. According to the Department of Energy in the Philippines, the minimum CN for fuels is 50.
So standard fuels have minimum requirements that need to be followed in order for it to reach the market. The minimum requirement will also depend on other items like emissions standards among other things.
There are two levels of premium fuels in the country. The next standard is 95 RON, which costs a little bit more than a litter of the standard fuel. The additional octane allows the fuel to resist engine knocking and premature detonation, meaning that it won’t have as much tendency to combust when you don’t want it to while it is exposed to high ambient temperatures. Then going up another level you get the 97 RON and up products. These fuels contain the most octane and will command a much higher price over regular fuels.
A premium diesel product, like a premium gasoline product, will feature more cetane in its composition, meaning that the fuel will have better ignition quality, fewer emissions, and more efficiency. Deposit build-up is also lessened with higher quality diesel fuels.
So is it worth it?
For gasoline engines, they say that more premium fuels offer better fuel economy, and that’s right if paired with an engine that needs it. If your car is designed to run on 91 RON fuels, then it won’t get too much benefit by going premium. Essentially, what higher octane fuels allow manufacturers to do is increase compression or the density at which air and fuel are compressed in the combustion chamber before it is ignited by a spark. The compression stroke in an engine produces heat, and that heat can prematurely ignite gasoline. Premium fuels are also recommended for most turbocharged and high-compression engines because of this factor, so if your vehicle’s manufacturer recommends premium gas, then you’d be darned sure going for premium fuel will be worth it.
However, if your car is not turbocharged or doesn't have high compression ratios, then don’t bother. If the manual states that 91 RON is sufficient, then follow that. You get more gas for your money, and if there are improvements, it's a margin of error or other variables at work.
For diesel engines, it is the same as following the manufacturer’s recommended octane rating in gasoline cars. If the manufacturer states a minimum cetane rating is enough, that should be what’s followed. You won’t get a huge performance increase just by going for premium fuels, but there is a benefit in the form of better efficiency and emissions as stated earlier. Cetane allows diesel to combust a lot easier, which also means quicker starting, and smoother idle if your engine can take advantage of higher cetane-rated fuel.
Again, this will depend on the engine that you are running, and if the manufacturer has a minimum requirement that needs to be followed, follow it, if not then just go by what is recommended and save some money at the pumps. Remember, what’s important is that you meet the requirements that the manufacturer posts, but if you’ve modified your car, go with what fuel you’ve modified your engine for.