lowcoaster

has anyone remapped their ecu for 91 octane?

gabe2006

US uses an average (RON+MON)/2 which means that 98-octane gasoline from Europe (RON) is on par with 93-octane in US. In the Houston area you can find 93-octane gasoline almost everywhere.

Dartmouth

Who are you referring to? Why do you ask? Seems a bit sarcastic.

Quadcammer

I'm referring to you.

why do I ask? Threads about running lower octane, rust on brake rotors, cost of mileage.

Just seems like you're more concerned with penny pinching then enjoying the car.

dasams

In order to decrease the amount of sulfur in gasoline, refiners will increase the operating severity in their hydrotreaters (see https://en.wikipedia.org/wiki/Hydrodesulfurization).

At the risk of oversimplifying a complex process, increasing the severity will increase the hydrogen uptake which saturates the double bounds resulting in a drop in octane. As an example, a high octane olefin molecule will be converted to a lower octane paraffin. This is what happened to the gasoline pool in CA in the 90's and it's coming to a gas station near you

Jaws1

No need to, nor possible (AFAIK). The ECU looks after it.

>91 is not readily available here, although the odd PetroCan does sell 94. Shell 91 works fine for my car. I'd rather run 91 w/o ethanol than 93 octane w/ethanol.

Chrono

+1

P0rsch3F113

Up here in my neck of the woods, have no problem finding Petro Canada Ultra 94.
On trips farther north, if no Ultra 94, will use Shell 91. If no Shell, anyone's 91.

Up here, never found anything other than Petro Canada that carries 94 (which is what my dealer service rep and my indy both recommend).

Dartmouth

Hey Quad whatever your name is. I see you like to talk....7400 posts. What do you read everyone's posts and then cut them down. What difference is it to you what I write about. You pick a couple topics and then bash away. What about the ones that people on this board have positive things to add. No stupid comments? The octane question is about engine knock not the cost of gas. If you don't like what i write about don't read it. Those who hide behind the internet with crap to say are cowards. Maybe you should keep your big mouth shut. And I'm talking to you.

Quadcammer

woah, I didn't realize you'd be so offended. Its just a car man, not that serious.

If you'd like to discuss octane and its affect on your vehicle in person, I'd be happy to do so.

Domer911

On the chance that you're confused, you may be referring to the fact that many refiners are reducing their conventional octane to sub-97 levels. (most common is 94). This, when mixed with 10% ethanol, delivers finished product with 97+ Octane rating.

The sub-octane route is the refiners' best way to get control of the title to the ethanol gallons that are blended, helping them cost-effectively (relatively speaking) hit their renewable mandate. This phenomenon has forced many terminals out of the clear, or conventional 97 business, so that every gallon coming out of the pipe gets blended with ethanol.

If it sounds complicated, it is. It's a ****ty, wasteful government program that does the exact opposite of what it was intended to do. It raises the cost of food and fuel, and does nothing to reduce dependance on foreign oil. Welcome to America.

Dartmouth

Yea right, I want to talk to you about octane. You didn't contribute a single informative thing about it on this thread. Go back and read the other intelligent members posts re: octane and its effect on a 3.8 and you might learn something. I know I did. End.

vern1

Since you both live somewhere in NJ, I don't think he was really thinking you would meet to discuss octane.

I believe there is a ton of good info on this subject of you search.....

Anyone know the best oil to use ?

Dan in Florida

+1. Farmers and inner city democrats have found common ground. The ethanol subsidies and food stamp programs generate the votes in congress to keep growing both programs. To hell with basic economics; it's all about incumbents raising money for re-election.

slicky rick

sorry guys some post here just make me smile….