Low octane gas



can i use low octane gas for my 2002 hyundai xg350? am a student and the gas prices are making me think twice?


does your owners manual say to use premium? if not regular would be fine.


Your owner’s manual is the only authoritative source for this answer. If it says a specific octane is “required” then you must use what it says. If it says it’s “recommended” then you can safely use a lower octane possibly at some compromise in performance.

   The owner's manual will say that it must have high octane or that it may use regular but should use high octane or regular is recommended.  The parts the leave out are:
  • If it needs high octane, using regular can damage the engine.

  • If it should use high octane then it has a system to sense the low octane and to make adjustments to the car that will protect the engine. However the adjustments will result in lower mileage (reducing or wiping out any economic advantage) and will reduce the power, defeating the reason most people buy cars that require high octane.


Don’t let high prices fool you into buying junk gas. It’s one of the biggest mistakes we see here at the Ford dealer I work for. As the others advise, use what it should have octane-wise but dont get gas from some hole-in-the-wall station where you would never have bought from in the past. Even at these high prices the cheapo stations are cheaper for a very good reason. Just exactly how cheap is it when it costs you a $500.00 tow and fuel pump job ? Here’s another misconception of the high prices, the electric in-tank fuel pumps these days need to be in some fuel for cooling purposes. Never, never run less than a quarter tank of gas, and NEVER run out of gas. It’s an investment that you only need to make once, then put that same $20 in each week on the top end. One more way to know if your car wants a higher octane fuel…if you’re trying to accelerate up a long grade and you hear you engine “pinging” of kackling, you need the next higher grade gas.


it says use unleaded pump octane rating 87 and 91 RON


Then it’s fine to use 87 in the US or Canada. If you’re in Europe or other parts of the world, the low-octane gas is 91 RON.


There is no such thing as “junk gas” just bad fuel stations. The fuel brand name is irrelevant its the tanks that are placed in the ground that matters in the very rare cases you mention.

Off brand stations typically buy the ends of branded fuel tankers at slightly cut rates that do not want to return to depot partially full. I worked at one New England chain(college) that did this and it was latter confirmed by a friend in the gasoline transport business. Sometimes you even have premium fuel in regular fuel tanks albeit blended with whatever is already there.

Not sure where you live but my state closely monitors ground water adjacent to fuel stations for evidence of leakage and makes fuel stations change tanks as matter of course.


but dont get gas from some hole-in-the-wall station where you would never have bought from in the past.

Are you saying these hole-in-the-wall stations have their own refineries?? THEY DON’T. They buy their gas from anyone who’ll sell it to them.


thank you guys! you’ll are the best :slight_smile: