The manual says that regular gas can harm the engine. Any real expert, including Porsche engineers, say that the only reason auto manufactures say to use premium fuel is to support the horse power rating. If Porsche engineers say you can use regular gas in a Porsche, I would think it would be ok in an Acura.
But the phrase "regular gas can harm the engine" - how? Any truth to this claim?
Thanks!
This comes up all the time. The correct answer is YES it CAN harm the engine. The higher the compression ratio and combustion pressures inside the cylinder, the higher the octane rating of the fuel must be to prevent a condition called detonation from developing. Unlike normal combustion, which is a controlled (but very fast) burn of the fuel/air mixture in a wave across the cylinder, detonation is an actual explosion, causing hammer blows to the inside of the cylinder. However, most modern high compression engines control the spark advance, valve timing and fuel injection via a series of sensors. If the sensors detect the sound of "knocking (detonation)" in the engine when fuel of too too low octane is being used in the engine, the computer will adjust things to stop/limit the knocking. IF you drive the engine gently, you most likely will not hurt the engine, but your ability to drive the car as designed is gone. Just one heavy acceleration with a defective knock sensor and the engine can be toast.
So, running fuel below 91 octane in the engine means you are relying on these sensors to catch detonation and pre-ignition quickly enough to protect the engine from damage. You are betting on them working perfectly. If you blow a hole in a piston, bend a connecting rod or burn and swallow a valve, you're looking at a new engine. Compare the cost of a new engine with the additional cost of 91+ octane fuel over
87 over the life of the car and you'll see it is worth protecting the engine.Run it on 91 or better, enjoy the power without fear of blowing the thing up.
If you are ever caught having to use regular fuel, don't fill the tank, drive the engine as gently as possible and get premium into the tank as quickly as possible. Continue to drive gently until the second fill up.
One last point. Don't run regular and dump octane extenders into the tank to get you to "premium". You are relying on perfect mixing, perfect proportions by volume and compatability with the fuel system, especially the injectors. And, ironically, it is more expensive than running premium.
Paul
Jim Crugnale wrote in news:e4bcfc0c-aae1-4ac4-b531- snipped-for-privacy@w9g2000prg.googlegroups.com:
What pj.chris says is substantially correct.
What Porsche and Honda do inside their engines have nothing to do with one another; apples and oranges, as they say. Honda designed the TL's engine to use 91-octane on a regular basis, not 87-octane. Therefore, 91 is what you should use.
The use of 87-octane is permissible if that's all that's available at the time, but you should not use it as a matter of course.
"regular gas can harm Acura's reputation".
But: the computer will tell all. If OBD shows indications of the "wrong" fuel, Acura can and probably will use that to deny appropriate warranty claims.
I asked that question to the Mercedes salesman that sold me a 500SL and his answer was that I only don't get the same performance. It will not damage the engine. May be they have sensors that Acura doesn't or may be the salesman doesn't know much about cars.
John
And if you check their warranty, you will find that running regular on anything but an emergency basis will void the warranty on the engine. Their sensors are no better than anybody elses and salesman wouldn't know detonation and what causes it if he/she tripped over it.
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.