Does 98 Octane Give More Power?

[adrian_celati]

Hi,

I've got a BF MkII XR6 turbo and know that the 245kw at the engine is achieved on 95 octane fuel.

As the ignition timing is controlled by the computer does this mean that you get more power on 98 octane? Does the computer advance the ignition further when you use 98 octane?

Has anyone done any test to see how much more power 98 octane gives the engine?

Thanks

[Iconic Bionic]

For the few extra cents, its probably worth using 98. Nearly all of us that have access to 98 use 98. If your tuned then definatly use 98.

I.B.

[ENVY-T]

Oh mate it's bl00dy amazing the difference. There is about .240 kws more. (notice the ".") lol.

[Pete A]

Use 98 if you can afford it. More power? I haven't really noticed it. More Km's to the tank? - for sure.

[Scrotus]

For sure you get more power, I know because my trusting wife fulled up with 95.... I noticed the difference. Either way car is now tuned for 98 so it gets it regardless.

[aiboart]

AutoSpeed

Issue: 247 Section: Special Features 15 September, 2003

The XR6 Turbo According to Ford - Part One

--extract of part one---

We talk to one of the key men behind Ford Australia's Falcon XR6 Turbo...

Interview by Michael Knowling and Julian Edgar, Pix by Julian Edgar

The background of Ford Australia's Gordon Barfield:

"I've been in Ford for over thirty years. My most recent experience from about 1995 is time with Tickford, or FPV as it is now, as the program manager and planner; so I've been involved in all the XR products all the way from EL, GTs and T-series. I was involved in getting the turbo engine and the 4-valve V8 up and running - it was my involvement really that made it all happen.

Issue: 248 Section: Special Features 22 September, 2003

The XR6 Turbo According to Ford - Part Two

---extract of part two---

Tell us about the activity of the knock sensor and how the engine management system uses its input.

"Well, the knock sensor is active on all of our engines - it's optimising to where you want to be. I don't think it's active above 4000 rpm, though and for details on how much timing is removed I'd have to talk to the calibration engineer. All of those sort of details I'd really need to confirm with him."

Is it likely that the engine will make more power on 98RON fuel than normal fuel (about 96RON)?

"It is conceivable but, again, I'd need to confirm.

"We run AFRs quite rich at full load in order to cool valves, pistons and the like. When you look at fuelling versus torque graph, you can - if the curve is flat - over-fuel to a degree without losing performance."

When Ford Australia releases a power curve for the XR6Turbo, is it a power sweep or stepped power outputs plotted together?

"When we plot a power curve the engine is held at each rpm interval - it's not a sweep. The curve is derived from a stabilised output all the way through the revs."

....

Autospeed XR6T genesis Part Part 1

Autospeed XR6T genesis Part 2

Autospeed XR6T genesis Part 3

Regards,

aa

[ratter]

Your car, if standard is tuned to run on a minimum of 95 octane, but even standard it may have some knock retatrd happeing on this fuel, so if it is, your car will benefit from using a higher octane fuel. Using a higher octane fuel will eliminate or slow down some of the knock retatrd from happening, so the car will pick up some power.

E85 does have a higher octane than 95 and even 98 fuels, but if standard, your car will not benefit using it over 98 as the 98 should pretty much stop all knock retatrd.

Also the calorific value of E85 is less then PULP, so you will use a lot more fuel to do the same distance

If tuning the car and using E85 you should pick up a little more power over other fuels because of the extra timing you can run, but this comes at a cost of having to use larger injectors and possibly larger fuel pump than you would need using PULP.

[NVT]

Ratter,

So does that mean that even when stock as a rock, you shouldn't use Regular 91 Unleaded?

[seventytwo]

91 can be used but, you will be down on power and use more fuel

95ron should be the minimum octane used for standard running and only use 91 if you are desperate.

Really the difference between filling up with 95 and 91 is only about $3 so why would you bother with the cheap and nasty fuel.

[MYBAXRT]

Edited 15/04/09 06:37 AM by seventytwo
no need to quote the post above your own