2.0 Turbo octane

desertdude59

desertdude59

Member
This is my first turbo vehicle so I was curious what octane everyone was putting in their 2.0. The manual said 87 was ok, but higher octane would make it run better. I put 93 in it tonight just because most turbo engines like high octane gas. What's everyone's thoughts?
 
Octane is a funny thing...

If your engine computer senses a knock (detonation/ping) it will retard the timing (and other changes) which will cost you some power & efficiency.

More octane increases the detonation resistance but so does increase in elevation and cooler ambient temperatures. Every 1000 feet of elevation at 70 degrees F would allow you to lower the octane rating by one point. Every 10 degree drop in temperature does the same.

If you live at sea level and its hot, odds are you should be running the premium to get the most out of your car.

Pay close attention to your actual fuel milage (using your odometer and fuel receipts) running premium for a month while driving normally then do the math for MPG, make the switch to regular and do the same. If your fuel milage increases with one Vs the other odds are it is making more power. Now compare the cost difference of the fuel and decide if its worth it.

Note: Some PCM's learn where the knock threshold is and adjust the programming accordingly, however they may not immediately adjust back the other way just because you put the premium gas in. PCM's will test themselves and make adjustments when certain drive cycles are met like only if it is between 65-75 degrees ambient temperature when the engine is started and the intake air temperature is within 2 degrees of ambient after 5 minutes and the moon is full, and you are traveling west at 52 MPH for exactly 3 minutes. Some drive cycles are ridiculous...

But there is probably a way to get you PCM to reset before you start each test I don't know what Jeep requires but my Acura just had to have the battery disconnected for 5 minutes to reset. The Acura would change tunes if sensed a knock and seemed like it would never go back until the battery was disconnected.
 
CalSgt said:
Octane is a funny thing...

If your engine computer senses a knock (detonation/ping) it will retard the timing (and other changes) which will cost you some power & efficiency.

More octane increases the detonation resistance but so does increase in elevation and cooler ambient temperatures. Every 1000 feet of elevation at 70 degrees F would allow you to lower the octane rating by one point. Every 10 degree drop in temperature does the same.

If you live at sea level and its hot, odds are you should be running the premium to get the most out of your car.

Pay close attention to your actual fuel milage (using your odometer and fuel receipts) running premium for a month while driving normally then do the math for MPG, make the switch to regular and do the same. If your fuel milage increases with one Vs the other odds are it is making more power. Now compare the cost difference of the fuel and decide if its worth it.

Note: Some PCM's learn where the knock threshold is and adjust the programming accordingly, however they may not immediately adjust back the other way just because you put the premium gas in. PCM's will test themselves and make adjustments when certain drive cycles are met like only if it is between 65-75 degrees ambient temperature when the engine is started and the intake air temperature is within 2 degrees of ambient after 5 minutes and the moon is full, and you are traveling west at 52 MPH for exactly 3 minutes. Some drive cycles are ridiculous...

But there is probably a way to get you PCM to reset before you start each test I don't know what Jeep requires but my Acura just had to have the battery disconnected for 5 minutes to reset. The Acura would change tunes if sensed a knock and seemed like it would never go back until the battery was disconnected.
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Ok cool. I'll have to try this out. I'm at 3,000 ft and it's cold here in the winter. It was probably around 34 when I got gas last night. I just don't want to ping my engine to death on cheap gas. I also don't want it to retard the timing and lose power either.
 
desertdude59 said:
This is my first turbo vehicle so I was curious what octane everyone was putting in their 2.0. The manual said 87 was ok, but higher octane would make it run better. I put 93 in it tonight just because most turbo engines like high octane gas. What's everyone's thoughts?
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We've had ours for about three years and started with 87 octane because the manual said to. It was pinging on hills during acceleration. We switched to 91 and it was fixed. I decided to try 89 for kicks, and it worked as well. Been running 89 for months now.

As far as performance, I've always felt that it ran the same regardless of octane.
 
WJCO said:
We've had ours for about three years and started with 87 octane because the manual said to. It was pinging on hills during acceleration. We switched to 91 and it was fixed. I decided to try 89 for kicks, and it worked as well. Been running 89 for months now.

As far as performance, I've always felt that it ran the same regardless of octane.
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Yeah we have lots of hill in West Virginia. Nothing is flat here. Plus I'm running 35s so that may put a little more load on the engine.
 
desertdude59 said:
Yeah we have lots of hill in West Virginia. Nothing is flat here. Plus I'm running 35s so that may put a little more load on the engine.
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We've run 35s on ours pretty much the entire time. Has plenty of power even on a Sport with the higher differential gears.
 
WJCO said:
We've run 35s on ours pretty much the entire time. Has plenty of power even on a Sport with the higher differential gears.
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I bought mine already set up so I'm not sure what gears mine has in it. It has to have been re geared because it doesn't hunt for gears when driving or anything. The speedo is right on the money too. Mine is a Willys so I know they came with 32s from factory.
 
I've been running 87 in mine. One thing I've noticed with this 2.0T vs other rides I've owned is while it's warming up on cold mornings, it really produces a ton of smoke from the rear. After it's warmed up, it's better. I was like WOAH!
 
rubi_vette said:
I've been running 87 in mine. One thing I've noticed with this 2.0T vs other rides I've owned is while it's warming up on cold mornings, it really produces a ton of smoke from the rear. After it's warmed up, it's better. I was like WOAH!
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Maybe its from the turbo. Mine does the same thing on cold mornings.
 
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