that pinging is called spark knock.....and i really dont see whats so wrong with running 93 in your jeep (hawaiian808) is rite 93 burns more efficiently so u burn less fuel but if u try it ur not going to see a difference in the first fell up.....but ur biggest diference come from where u get ur fuel i only run Shell fuel in mine walmart fuel suck ***

 

I run 87, occasionally 89, and I only use Quiktrip gas. I get up to 2 full mpg's better when I drive the extra 2 miles to QT. I find it way worth it.. and a lot of times, cheaper!

 

I always use the lowest grade. I average 22mpg, most of my driving is highway. I can't see my mileage getting any better than that.

My friend used to use Sam's Club gasoline in his 2005 Honda Civic (already has 212,000 miles on it!). It had problems one day, he had it towed to the Honda dealer. Turns out it had bad gas in it that did damage to the motor. Over $3000 to fix.

 

O.O WOW!
I'm very lucky to get 16...

 

Read the owners manual whatever octane it says to use is best,Running a higher octane can cost you a few mpg and the price is more.Some of my friends have been toying with running 20% ethanol but its all in newer cars that can handle it.

 

DaveVmax I like your choice of vehicles, I have an 01 audi s4 its 93 all the time with 87 in the Jeep but I found I got 2mpgs better when I run the Jeep on 93 too.

 

Shell vpower 91. It's got NO ethanol...which other fuels may have to actually bump octane ratings. Here in Alberta anyways.

 

oh yes. i have the 93octane chip so i cant even run less lol

 

There's nothing wrong with running 93. If that's what makes you sleep at night that's fine. It's just completely pointless. I wish you could actually time these things. I would be willing to run 93 if I could crank the timing up. That's always my first modification to a vehicle is see how much timing I can get out of it. It's amazing how much it wakes it up and improves fuel economy. When my mustang was stock with bolt ons I had 12 degrees over stock base timing in it. Nobody ever believed it was stock the way that thing ran, and I could milk 30mpg out of it on the highway.

 

The renix fuel injection manual tells me the ecu can control ignition timing on single, or groups of, cylinders. I also have a knock sensor. If that's the case, nobody can seriously tell me running higher octane gas is pointless. Engine controls like this are the REASON high octane fuels even exist. Ya, its not a ferrari, but in my mind its worth it for high octane.

 

Maybe the study was based on ecu's that can control timing, like I said everything I run 93, higher grade and makes me sleep better at night, all I noticed when I switch over was a better idle

 

I used to run 93 in my jeep but when I switched back to the cheap stuff I saw no difference in mpgs or the way it ran.

 

An old guy in my town tells me that since 93 doesnt sell alot as 87 it sits down in the tanks and gather crude and doesnt get mixed up alot like 87 does and i believe him to but thats his theory

 

I have a station in town that sells ethenol free fuels... I always fill up there 87 oct

 

That's sweet. I've been told ethanol degrades fuel lines quicker on older vehicles too. I also have an 08 caravan. It's got the E85 badge. The owners manual says something along the same line, ie: "fuel lines compatible with E85..."