[Tcamaro]

Originally Posted by MovieGuy

I am trying to find the article I had bookmarked about this technology. But it advances the timing in real time. The engine has knock sensors on each side of the block that detect engine knock and adjust for it as it happens. Ford claims this process can increase the horse power of their 3.7 by 7 to 12 horses when adding 91 or 93 octane gas because of the advancement of the timing.

So it sounds like they try and take advantage of the higher octane because of the soul purpose being able of changing the timing on the fly based on feedback. That being said there is a power advantage based on fuel.

[Oil Man]

Originally Posted by cellsafemode

Each cylinder has timing control, then you have vvt (VTEC) which in conjunction with the timing helps produce more power.

They accomplish similar goals, but they work differently.

GM's VVT system uses a phaser plate to advance and retard the camshaft according to power demand, where VTEC engines actually have camshafts with two separate profiles that engage and disengage rockers between the more and less aggressive profile.

[Oil Man]

Originally Posted by KoolHyperBlue

On a side note I've read some people in this thread using 91 octane . I wouldn't take that risk

If you live in the western half of the country, chances are that you don't get a choice. 91 is the highest rated fuel that's widely available. And it works just fine.

I have blended up my own 93 octane by combining the proper ratios of 100 octane unleaded and 91 for the sake of experiment, but if there was any significant gain, I couldn't tell.

And again, depending upon which market you live in, the actual differences between brands of fuel can be non-existent. Las Vegas has many different brands of fuel for sale, and zero oil refineries. In fact, all of their fuel comes to town in the same 14" pipeline, regardless of which California refinery 300 miles away actually made the fuel.

[Slem]

Originally Posted by MovieGuy

We have a lot of gas stations where the 91 octane is marked 10% ethanol. I don't know about shell stations.

Ya honestly I would definitely stay away from any octane rated @ 91 containing 10% ethanol, it means it's 87 that is boosted to 91, you are safer using 93 or 94 with 10% ethanol or even better use 91 and up with no ethanol if you can get it.

[MovieGuy]

Originally Posted by Slem

Ya honestly I would definitely stay away from any octane rated @ 91 containing 10% ethanol, it means it's 87 that is boosted to 91, you are safer using 93 or 94 with 10% ethanol or even better use 91 and up with no ethanol if you can get it.

We have two stations in town that sell gas without Ethanol. One of them sells 87 and 91, the other one sells 91 and 103. So far I have been using 87 but this next time I fill up I am going to try 91 and see what it does.

[hotlap]

Straight 91 octane has about 3% greater energy density than 93 with 10% ethanol.

[davet435]

Ethanol free gasolines. Interesting, most in my area seem to be unbranded. I think the only ones I would trust would be the race fuel stations.

http://www.pure-gas.org/index.jsp?stateprov=TX

[SpeedLimit]

No pure gasoline stations in my metropolitan area. I would buy gasoline if it was available... This area, I top off at Costco to save 8% err 4%

[MovieGuy]

Originally Posted by davet435

Ethanol free gasolines. Interesting, most in my area seem to be unbranded. I think the only ones I would trust would be the race fuel stations.

http://www.pure-gas.org/index.jsp?stateprov=TX

Here in Topeka gas that is ethanol free is branded ethanol free. They don't have to tell you if there is any ethanol in it in Kansas anymore.

[GroundhogSS]

Here's what AAA says about the benefits of Top Tier gas.


http://www.corvetteforum.com/article...mpaign=content

[Branight]

Don't have much of a choice where I live, it's either Conoco/Phillips or Shell. Would give my left arm to have a QT in town.

[mt3130]

There are a lot of ethanol free stations by me, but most have 87 or 89 octane ethanol free. A few have 90 octane, and only the local airport has 91 and 100 octane.