87 Octane vs 89 Octane..
Champion
Joined: May 2009
Posts: 3,497
Likes: 1
From: MN
Also the hemi in my 09 is quite a bit different than the one in your 04.
Record Breaker
Joined: Nov 2009
Posts: 1,077
Likes: 0
From: Austin, TX
I made 2 test runs while towing a 4200lb travel trailer in hill country.
200 miles with 89
200 miles with 87
Dogged it pretty hard to check for detonation which as I recall from the 60's thru 80's sounded like "pinging" or "clattering".
Didn't hear nuthin but that darn truck is so quiet inside I coulda missed it.
Summary: I use 87 all the time except for towing when I use 89 to be on the safe side and 93 ONLY when I have a Superchips tune installed.
p.s. Speaking of quiet cab; I took my truck into the dealer for 6,000 mile service and a couple of nit picky warranty items. To my surprise, my "additional/extended" bumper to bumper warranty provided for a FREE rental vehicle.
The rental car company picked me up at the dealership and chauffered me to the rental lot in a brand new Cadillac Escalade and that beast was noisy, noisy, noisy inside...road noise and drivetrain noise.
Then the rental car I got was a Dodge Nitro. Comfy car but horribly noisy.
Sure will be glad to get the Ram back tomorrow.
200 miles with 89
200 miles with 87
Dogged it pretty hard to check for detonation which as I recall from the 60's thru 80's sounded like "pinging" or "clattering".
Didn't hear nuthin but that darn truck is so quiet inside I coulda missed it.
Summary: I use 87 all the time except for towing when I use 89 to be on the safe side and 93 ONLY when I have a Superchips tune installed.
p.s. Speaking of quiet cab; I took my truck into the dealer for 6,000 mile service and a couple of nit picky warranty items. To my surprise, my "additional/extended" bumper to bumper warranty provided for a FREE rental vehicle.
The rental car company picked me up at the dealership and chauffered me to the rental lot in a brand new Cadillac Escalade and that beast was noisy, noisy, noisy inside...road noise and drivetrain noise.
Then the rental car I got was a Dodge Nitro. Comfy car but horribly noisy.
Sure will be glad to get the Ram back tomorrow.
Last edited by 05Dakotaho; Aug 3, 2010 at 06:39 PM.
Veteran
Joined: Jun 2010
Posts: 255
Likes: 1
From: Northern California
I could give a rat's a$$ what the manual says I know that in EVERY case I've seen a failed compression test or a dropped piston in a modern Hemi, the owner either admitted to running 87 octane on the spot or 'fessed up to it later. And unless you are hooked up and monitoring for it, there is NO WAY of knowing if there is a pre-detonation happening unless it's severe if you are hearing a knock, you are causing irreversible engine damage.
Run you your 87 octane fuel every tank full, odds are you'll never have an issue, but nothing you can say or show in a manual will have me believe that the CHANCES of a major engine problem is not increased. I've seen what pre-detonation does with my own eyes... Going down a one way street at 90 mph doesn't mean you'll have a head on either, but I like my chances better if I was heading the right way. LOL...
Personally, I think it's VERY irresponsible of Chrysler to even put that in the manual. They are in essence leaving the burden of being able to tell if there is sufficient ping or knock or pre-detonation on the owner of the vehicle! If you design an engine that performs at peak efficiency at 89, then either state that 87 octane is NOT to be used OR design the thing with stereo knock sensors and a tune that will pull timing when necessary!!!
Run you your 87 octane fuel every tank full, odds are you'll never have an issue, but nothing you can say or show in a manual will have me believe that the CHANCES of a major engine problem is not increased. I've seen what pre-detonation does with my own eyes... Going down a one way street at 90 mph doesn't mean you'll have a head on either, but I like my chances better if I was heading the right way. LOL...
Personally, I think it's VERY irresponsible of Chrysler to even put that in the manual. They are in essence leaving the burden of being able to tell if there is sufficient ping or knock or pre-detonation on the owner of the vehicle! If you design an engine that performs at peak efficiency at 89, then either state that 87 octane is NOT to be used OR design the thing with stereo knock sensors and a tune that will pull timing when necessary!!!
All Star
Joined: Jan 2009
Posts: 801
Likes: 1
From: Bristol, NH
I run 89 in my truck because the Manual recomends it and my company pays for my fuel. My wife uses 87 in her Jeep with the Hemi because she doesn't care. I have had no issues with either, my truck does get bett mpg's but I doubt it is because of the fuel grade.
Veteran
Joined: Jun 2010
Posts: 255
Likes: 1
From: Northern California
Running any higher than 89 is a waste of money, unless you run a tune on your truck and set it out side the factory parameters. The difference would be 1 octane and a dilution of fuel with ethanol, which usually means a little less mpg and fewer corn on the cob at the dinner table.
Registered User
Joined: Aug 2010
Posts: 13
Likes: 0
I have an 03 hemi ram 4x4...210,000 km (100000km=62000 miles) 87 octane from day one and still running strong...just bought a '10 hemi laramie last week...it will get the 87 octane as well....and the 03 will now be a huntin truck and will still drink 87...no mechanic here..just experience with my truck..
Captain
Joined: Mar 2005
Posts: 639
Likes: 0
From: Dyess, TX
Running any higher than 89 is a waste of money, unless you run a tune on your truck and set it out side the factory parameters. The difference would be 1 octane and a dilution of fuel with ethanol, which usually means a little less mpg and fewer corn on the cob at the dinner table.
90 octane will drive just like 89 and you will get about 4% worse gas mileage (if you believe the math. E10 has 96.6% of the energy of regular gas).
Ethanol has no affect on the corn on the cob supply. Ethanol comes from feeder corn so will affect the price of meat much more quickly than table corn. Obviously everything in an economy interconnects so there maybe ripples in unexpected directions.
Record Breaker
Joined: Jan 2010
Posts: 1,400
Likes: 5
From: San Pedro, California
Recommended does not equal required, so if you run 87 and you have engine problems, it was not the gas.
I know some of the other members "know from the school of hard knocks", but today's technology is much better at managing the engine so the 87 is not a problem.
