1. Home
  2. Volkswagen, everything else
  3. v6 on regular?

v6 on regular?

On Jim Healey's online chat in USA Today today I read this:

"But even Porsche's high-strung turbo engine are regular-grade safe. Porsche's chief engine engineer told me, in effect: Are you kidding? We sell these things around the world; they have to be able to run on the worst gas you can imagine.

Octane measuers only the ability of gas to resist detonation. High-octane gas is harder to ignite than low-octane gas is. Thus, you can squeeze high octane tighter, via high compression ratio or blower, without the heat of compression causing pinging or pre-ignition or detonation. If you use low-octane, knock sensors on cars today retard the ignition timing automatically when they 'hear' a ping, to prevent damage. You lose a skosh of power via the retarded timing, but you're unlikely to notice."

I wonder when I could reasonably use low octane gas (89) in my v6 and if it would raise the low end of my usable power band.

My request to Jim to evaluate VAG-COM did not appear.

btw, my 2K mile round trip to Wisconsin was nice with the GLI v6 6 speed. 80-90mph and higher seems do-able all day as long as someone else is going fast 1/4 mile ahead. I saw one pack leader get pulled over for speeding (in VA).

Sam

Reply to
sheinrich
Loading thread data ...

No, it is not going to raise any power bands and will lower some. It will also likely use more fuel and may end up costing more. (all that is assuming your 89 had all the right computer equipment) If it does not have all the right computer equipment, it may damage your engine.

Reply to
Joseph Meehan

You get the best performance and efficiency when you use the recommended octane. Porsche, VW, etc engineers know that the gas at times isn't the best along with knowing CHEAP owners not wanting to spend the $5 to fill the tank with premium versus the cheap stuff. The ECM does a great job of adjusting timing to compensate for poor fuel or cheap owners.

Reply to
Woodchuck

It's true. All modern engines have knock sensors and will retard timing (and some turbo cars will limit boost) if they sense a knock. Typically, high compression (and turbocharged or supercharged) engines recommend higher-octane fuel so the engine management will keep the timing (and/or boost) set at the optimum level for maximum power. There is little (if any) chance you will damage a modern engine by using a lower-octane fuel. Try a tankful and see if you notice a difference. That said, the gas supplier are more than happy that anyone would be afraid to put lowly "regular" in their high-performance car.

Even filling up with "premium" is no guarantee you won't have knock. I've had two engines (one turbocharged auto, one high-compression motorcycle) that were sensitive to the brand of fuel to the point they would only not ping on certain brands. On the motorcycle, I could run both mid-grade and premium Union 76 only w/o knock-- all other brands at all grades knocked. On the turbo car, it would only run w/o knock on Shell premium, else it would knock the max boost down from 14 to 9 psi (now THATS a measurable performance hit).

Reply to
CSS

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.