To the OP, I'm near 178K with mine, yes, I've had to do some repairs on it, all the u-joints, including the front drive axles, but now they are greasable, clutch, pilot bearing,upper and lower ball joints, blah, blah,blah----------but it still runs very strong, gets original gas mileage, I'm not planning on trading it any time soon!!

 

87 octane is costing your more in the long run the 5 bucks to ten, a tank you may think your saving, Read the owners manual, 89 IS the octane of choice by dodge for your hemi...

87 nets less mpg, and poor performance and opens up additional maintance and repairs, but its not my truck, so penny pinch to your hurts contant, cause your gonna need mega bucks down the line...

Running 93 octane when towing, or highway driving, is my personal choice, My hemi loves the stuff and I get better mpg.

 

I agree, I accidentally put a tank of 87 in a little while back, I could tell the difference almost immediately. I wont be doing that again, my truck runs a lot better on 89 or higher. Also, straight from the manual

87 Octane:
All engines (except 5.7L engines) are designed
to meet all emissions regulations
and provide excellent fuel economy and
performance when using high quality unleaded
“regular” gasoline having an octane
rating of 87. The routine use of premium
gasoline is not recommended.
Under normal conditions the use of premium fuel will
not provide a benefit over high quality regular gasolines
and in some circumstances may result in poorer performance

89 Octane
The 5.7L engine is designed to meet all
emissions regulations and provide satisfactory
fuel economy and performance when
using high quality unleaded gasoline having
an octane range of 87 to 89. The manufacturer
recommends the use of 89 octane
for optimum performance.


It says right in the manual under 87 that's its for the 3.7 and 4.7 liter engines, and 89 is for 5.7. Why would they put that if it wasn't the best route?

 

It also says in the manual under 89 that a good quality fuel with an octane range of 87 to 89 is acceptable in the Hemi, but for optimum performance they recommend the use of 89, but the Hemi will meet emission requirements and provide satisfactory performance, using good quality 87 octane. You need to read it all and not just what you want to see. My truck has proved the above statement, having travelled 106,000 miles with no problems on a steady diet of 87, and thats all I've been trying to get across, and it seems Dodge agrees with me. Why they make conflicting statements between the 87 and 89 paragraphs, I don't know. But I do know what my truck has done. Six years with one plug change at 50,000 miles and all 87 octane, whether yall believe it not.


You read the manual, and you will see that Dodge says 87 to 89 octane is acceptable, but 89 is recommended for optimim performance. I have run a few tanks of 89 through my truck and seen no difference in milage or pereformance at all. I'm sorry yours wont run on it.


I sure hope you are a better sailor than you are an auto technician, and you don't have to tell anyone what I,ve done, I will do that. I'm just simply pointing out all of your misinformation. It clearly states in my owners manual that MY year hemi will run acceptably and meet emissions standards using a good quality fuel with octane from 87 to 89, with 89 recommended for optimum performance. If your manual says something different, then you go by it, but dont get on here and think yours is the only hemi and the only manual. I haven't told anyone on here to change to 87, just told the story of my experiences. And I also don't give a rats @ss whether you believe me or not. Whats played out is your know it all attitude, your LACK of experience, and responses that aren't very well researched, or correct.. Have a good day sir

Your spark plug answer is also bogus as far as what I've experienced. People on here act like the modern Hemi needs TLC like the original 426 did. It's just a low compression V-8 engine in the truck version, and will perform perfectly well with adequate maintenance, and doesn't need optimum maintenance unless you are just looking for something to do with your truck. There's nothing special about these engines compared to other engines requirements. To keep 08 from blowing a head gasket, which he probably has no idea what they are, these comments are my opinions based on my truck



Dodge clearly realized that using 87 was causing problems with the 5.7 so to cover their asses they changed the manual to say a minimum of 89 was needed so that way if someone's engine failed due to the use of 87 (which there were) they couldn't be held responsible to cover it under a warranty.

Is this proven fact, or just your opinion???


*A separate topic but spark plugs play a HUGE role in the 5.7 because it's just a solid well known fact that if you don't want to chance any issues then you use the copper plugs over nickel, iridium or platinums


And where are these solid well known facts coming I've never recieved a bulletin from Dodge, telling me only copper plugs will work in a Hemi. Are you special and on a not so well mailing list


Well stated Jareski

[quote=Old Man with a hemi;2921350]*A separate topic but spark plugs play a HUGE role in the 5.7 because it's just a solid well known fact that if you don't want to chance any issues then you use the copper plugs over nickel, iridium or platinums

08
I'm not trying to be a smart-@ss here, but I need to know what issues you are talking about. A spark plug goes into a hole in the head and does nothing but produce a spark when prompted to do so. If it doesn't spark then the plug could be bad or a coil pack, or possibly a timing issue but not likely. Seeing that it doesnt move, and if a copper or platinum plug is sparking properly I can see no possibility for any issues caused by the right heat range plugs, and every plug maker out there designs their plugs for the engines that they are going into. I just can't imagine any issues that a different metal plug could cause, especially plugs with better conductivity than the originals. Anyone could get a bad plug, be it in copper or the other metals, but a bad plug still wouldn't cause anything other than a miss until you replace it. I have never in my life seen plugs of the right heat range, cause the slightest bit of damage to any engine, unless you might be spraying and the extra heat might melt the electrode causing it to fall on top of a piston. But then again, thats not the plugs fault

 

If you run 87octane, you WILL get predetonation.
Predetonation KILLS hemi engines because the piston ringlands are very close to the top of the piston(NASCAR style pistons). This leaves little material to withstand alot of detonation. They eventually break off and cause lots of damage.
Everythime your truck has detonation or Pre-det, the piston gets a mini crater in it. Do a search on the internet and you'll see. You actually lose some material. Yes Hemi's have knock sensors, BUT, you have to have some type of pre-det in order for the knock sensors to even trigger! When this happens, you reduce your overall power output AND get terrible gas mileage. So, by trying to pinch a few pennies per gallon at the pump which is only a couple of bucks a tank nets you less mpg's and less power. In the long run you risk damaging you engine that will costs several thousand to replace. More expensive than just putting in 89octane.
Dunno about anyone else, but I bought a V8 for the power. I could really care less about the mpg's actually. i think any truck that does better than 10mpg is good. Mine does, so the care stops there.

Also, higher octane fuels have better additives and cleaners, so your really get the best of both worlds!

 

And less or no ehtanol depending on your local stations. A bit more ethanol will cost you more in mpg than the few pennies a gallon.

 

It's almost funny you guys keep arguing about this, the OP is long gone....

 

Any time you have a spark inside a clossed chamber of flue it will burn, so yes a hemi will burn 87 octane inside the cylinder and chug on down the road with all eight cylinders.

You can breath 02 just fine, 20.9% is the standard level of oxygen in the atmosphere, so depending on your level of fitness, you could get by around 19%, but your not going to be feeling all that great and you could be dead.

89 octane in a hemi is abought equal to breathing 20.9 percant oxygen, 87 octane is not a effective flue for the hemi, nor is breathing in 19% oxygen effective for the average person.

so yup 87 is the mim standard of flue in a hemi, as I reed my owners man, I interput 87 octane is the bottom of the spectrum for effective combustion, where as 89 is on the higher end of the spectrum.

pass with a C or pass with a A+

 

As I've said MANY times before - seen a few Hemi engines that were replaced/scrapped due to a major cylinder failure and in EVERY case when I could get the owner to tell me "off the record" what fuel they ran - it's ALWAYS been 87 octane.

I've also talked to MANY Hemi owners with 150,000+ miles on their truck who boast to have NEVER run anything except 87 octane gas.

So, will you have a major engine problem if you run 87 octane? Probably not. But it just seems to be added insurance to me to run 89 octane. The only exception I would make is if someone is running a tune that specifically de-tunes the truck to safely run 87 octane.

That's my take anyway - take it for what it's worth...

 

Thanks Hammer, I've never told anyone on here to change to 87, but I am one of the ones that have run 87 with no issues for over 100,000 miles. I would still like someone to tell me what destroyed the engines you talk about, because a well tuned Hemi, should not pre detonate on the 87 fuel.Lke you said about a particular tune for 87, maybe some of these wasted engines were running a tune for higher octane fuels and still running 87 and didn't tell you that Thanks again for your comments