93 Octane

Discussion in '1994 - 1995 Specific Tech' started by BANGERSTANGER76, Aug 9, 2013.

  1. Placebo effect? Less rumblies and pinging from the engine? Who knows
  2. SMH as well.
  3. cant say 93 makes my Mustang run any better, but sure does feel better knowing I've a got a little extra protection from detonation, especially when the boost gauge gets into positive numbers :D
  4. This could have been a MotorVac service you saw. The chemicals in a MotorVac Carbon Clean service are proven to remove carbon from the intake valves and from the combustion chamber. Also the chemicals will make the catalytic converter operate more efficiently. I have tested this many times with a 5 gas analyzer and have always seen an improvement in the tailpipe emissions after performing a MotorVac service, even if the car was blowing very clean before the service. Part of the service is the chemical that is injected into the intake manifold and allowed to sit for about 20 min. on a hot engine. When re-started they smoke like a MoFo and that stuff stinks badly!
  5. I always bang my head with octane discussions. Just because 93 is more expensive than 87 doesn't mean better. Is it better for the engine? Depends on a ton of technical engineering criteria.

    Personally, i view fuel the same way as i view oil. What was the engine "designed" to use, and stick with it. Now, since we modify our cars with higher compression, advanced timing, boost, etc, we tend to run higher octane gas in order to prevent detonation and ruining our cars. But still to issue a blanket statement and say higher octanes are better is incorrect.

    My daily driver is a premium "recommended" car. That means for max performance it is recommended by the manufacturer to run 91+ octane. It will still run on 87 octane, but performance will be lesser. I drive nearly 500 miles a week, so i decided to experiment. I ran 93 octane for a month, then ran 87 octane for a month. I noticed zero difference at all in pickup, the way the car behaved, or fuel economy. At this point, i just grab whatever nozzle i feel like putting in the car now. However some coworkers have balked at me for putting "cheap, crappy gas" in and "ruining" the car.

    I used to love commuting in my '03 GT. Took 87 octane and 26MPG highway. I missed that.

  6. That's a pretty good description of what I saw. The only difference there might be is that saw these guys hook it up to the fuel rails.
  7. I run 87 octane almost exclusively in my Suburban. Unless I know I'm going to be towing. The Suburban is a Flex Fuel vehicle so it'll run on anything from the cheapest of pump fuels all the way to E85.

    I notice a pretty significant difference in how the truck acts when I put 89 in it for Towing. Knocking and pinging on accel or towing up hill are the most notable. Fuel mileage isn't affected much (if any) but it's nice getting that little bit of extra pull power going up a steep or long hill because the knock sensors aren't pulling a ton of timing out.

    When not towing... I'd be hard pressed to get the engine to ping. So it gets 87 under any other circumstance.
  8. The first part of the service the engine is run with the fuel/chemical mix from the MotorVac, the stock fuel lines are disconnected and stock fuel pump disabled so the engine runs on just the MotorVac system. After that service the intake cleaning chemicals are added to the intake manifold, usually through a vacuum port until the engine dies, then let sit for 20 min or so and re-start engine with stock fuel system hooked back up and run until the exhaust blows clean, sometimes this takes a while and more rpm is needed to clear all of the chemical out of the intake track and plenum.
  9. I'd be interested in seeing some real-world results of using 93 with increased timing and 87 with standard base timing related to fuel economy. With 87 around $3.50 and 93 around $3.70 where I am, that's a 6% cost difference. If you went from 20 to 21.5 mpg that would make it a net value to use 93, provided you do bump your timing, which 93 will let you do. I can't really do the tests because my turbo '95 would blow up if I tried 87. But I wouldn't write off 93 just yet.

    As for the Op's better shifting and smoother running, I think Detroit just hit a cold-spell like we have in Cleveland. We went from upper 80's in the daytime to a high of 68 yesterday. That probably has a lot more to do with it than the fill-up. It may even solve the shift improvement mystery.

  10. I'm not sure you would yield that much of a benefit from timing alone.

    On my 86 (when it was N/A) going from 87 to 89 worked out better for me. 93 did not.
  11. image012.jpg

    This is the cycle each engine cylinder makes. At point C is where your plug fires, igniting the fuel and increasing the pressure in the cyclinder creating the power stroke (labeled here as expansion). Your timing moves point C up or down the compression line. Depending on where your point C lies on that compression line, you may notice performance differences with different octane fuels. A higher octane fuel, like many have already correctly stated, resists igniting. If the fuel spontaneously ignites before the ignition point, you're running your engine like a diesel where the pressure alone ignites the fuel. This is where you would benefit from a higher octane fuel. The higher octane fuel will resist spontaneous ignition until the spark plug ignites it like the engine is designed to do.
  12. Like I said from jump street. I'm not an expert. I have owned 24 cars and I have NEVER EVER EVER EVER ran 93 gas in any of them. I decided to try it in my Stang and IMO it made the Stang CLEARLY run a little better. Why???? I dont know. I felt more pick up and to me it seemed the trans shifted a little tighter like a little more in sync. Not like I felt a 100 HP difference or anything it was minor. But it was there. I was so stunned. I made this thread. But when Kurt said the thing about carbon build up it made alot of sense to me. I'm fine running 87 gas. Especially with the amount of driving I do and the fact that I have ZERO interest in racing. Im all about Dream Cruising!!!!!! See you boys Saturday.
  13. My old engine wasn't really happy unless I put 100 in it. I'm not sure why. It would run on 93, but it would frequently get mid throttle pinging.

    I am impressed with all the new Flex Fuel technology. It's really neat that they have made these ECUs so advanced that they automatically adjust for whatever fuel you put in it. I just bought my first flex fuel vehicle this week.

  14. I dont think I understand what pinging is? Can someone please enlighten me?
  15. Slight detonation, sometimes called spark knock. Slight tinny sound, like someone is rattling a tin can in your exhaust.

  16. Unless your listening for it and know what the sound is most people will not notice.
  17. :pop: Just enjoying the show......

    I'm sticking with the Tarragon 116 from Dragon Race Fuels

  18. You can launch a space ship with that stuff. LOL.
    1163 horses. SHEESH!!!!! I want to see pics of that thing.