Jeep Commander Forum banner

1 - 10 of 10 Posts

·
Registered
Joined
·
389 Posts
Discussion Starter #1
I'm considering switching my programmer to premium fuel in my V6. It has 134,000 miles on it right now.

I'm wondering if there is potential for better mileage, power, or both, especially if I manage to get ethanol-free fuel since it's the lesser used premium grade. It's only going to cost me 10 cents more than regular at my local Speedway due to a promo, so I figure I'll try it.

Anyone see a potential problem with this?
 

·
Super Moderator
Joined
·
5,763 Posts
I'm considering switching my programmer to premium fuel in my V6. It has 134,000 miles on it right now.

I'm wondering if there is potential for better mileage, power, or both, especially if I manage to get ethanol-free fuel since it's the lesser used premium grade. It's only going to cost me 10 cents more than regular at my local Speedway due to a promo, so I figure I'll try it.

Anyone see a potential problem with this?
I don't see any issues with this;

You may even see a slight improvement in your MPGs.
 

·
Registered
Joined
·
480 Posts
I've played with reprogramming on mine with the Superchips 3872. I found that while there were slight power gains on 91 octane, the mileage gains weren't enough to justify the extra cost. A good 87 tune should be able to net you around the same mileage and close to the same performance.
 

·
Super Moderator
Joined
·
5,763 Posts
I've played with reprogramming on mine with the Superchips 3872. I found that while there were slight power gains on 91 octane, the mileage gains weren't enough to justify the extra cost. A good 87 tune should be able to net you around the same mileage and close to the same performance.
I have the Superchips (3874) F5 Flashpaq Tuner and I have the 93 octane performance tune loaded.

You can probably get close to the same mileage with a good 87 octane tune if your really dig deep and tweak some of the individual settings & shift points.

I can tell you definitively, you will not get anywhere close to the same performance of the 93 octane performance tune - with any 87 octane tune.
 

·
Registered
Joined
·
480 Posts
I have the Superchips (3874) F5 Flashpaq Tuner and I have the 93 octane performance tune loaded.

You can probably get close to the same mileage with a good 87 octane tune if your really dig deep and tweak some of the individual settings & shift points.

I can tell you definitively, you will not get anywhere close to the same performance of the 93 octane performance tune - with any 87 octane tune.
I can believe that with 93. Here in California, all I can get is 91, and there wasn't much difference between the 87 performance and 91 performance tune. I ran a lot of tests with the three non-towing tunes that came on mine, which were 87 eco, 87 performance, and 91 performance. 87 eco ran the best mileage numbers on mine, and killed all power, but the two performance tunes were nearly identical for me.

Of course, the difference likely comes down to our motors. There isn't much power to be gained out of these early Hemis without some major modifications or custom tunes. I've done a lot of playing and haven't seen any major gains out of anything I've done to it.
 

·
Registered
Joined
·
205 Posts
I have the flashpaq tuner for my 5.7 Hemi Commander. I tried the 93? tune but did not at all like the way the throttle at low speed became so very sensitive. Definitely not what you want when crawling slowly off road. Most vehicles that are tuned for higher octane will get worse fuel economy when running lower than recommended octane fuels as the engine management system monitors the knock sensors and retards the ignition timing and injection timing to prevent engine detonation with lower octane fuels. This does not hurt anything at all but performance is less and fuel economy will suffer slightly, It really isn't a huge difference. I run the 87 octane tune with my flashpaq tuner. Has little more performance than stock but regarding fuel economy, I have not been able to see a difference compared to the stock tune. With electronic engine management and injection systems making any changes with free flowing exhausts or intakes usually does not equate to much better performance or fuel economy as the system monitors the oxygen sensors, knock sensors and adjusts the mixture and timing to compensate for more free flowing intake and exhaust. Rarely if ever this will translate into better fuel economy as the engine requires the proper fuel mixture to run correctly.
 

·
Super Moderator
Joined
·
5,763 Posts
I have the flashpaq tuner for my 5.7 Hemi Commander. I tried the 93? tune but did not at all like the way the throttle at low speed became so very sensitive. Definitely not what you want when crawling slowly off road.
I use the 93 Octane tune for normal everyday driving.

If I'm towing, I program in the towing tune.

If I'm off-roading/trail riding I'll re-program it back to stock.
 

·
Registered
Joined
·
338 Posts
I have the flashpaq tuner for my 5.7 Hemi Commander. I tried the 93? tune but did not at all like the way the throttle at low speed became so very sensitive. Definitely not what you want when crawling slowly off road. Most vehicles that are tuned for higher octane will get worse fuel economy when running lower than recommended octane fuels as the engine management system monitors the knock sensors and retards the ignition timing and injection timing to prevent engine detonation with lower octane fuels. This does not hurt anything at all but performance is less and fuel economy will suffer slightly, It really isn't a huge difference. I run the 87 octane tune with my flashpaq tuner. Has little more performance than stock but regarding fuel economy, I have not been able to see a difference compared to the stock tune. With electronic engine management and injection systems making any changes with free flowing exhausts or intakes usually does not equate to much better performance or fuel economy as the system monitors the oxygen sensors, knock sensors and adjusts the mixture and timing to compensate for more free flowing intake and exhaust. Rarely if ever this will translate into better fuel economy as the engine requires the proper fuel mixture to run correctly.
I have the diablo intune which allows you to make the throttle more or less sensitive in 1% inc. ... I ussually run at +17%, anything over 20 messes with driveability, but in your case you could go negative.

To the OP, with 170,000 miles, I use the premium tune.... runs much better. Stock tune has surge issues. Don't use the premium tune with regular fuel or it will knock under heavy acceleration or load.
 
1 - 10 of 10 Posts
Top