Actually, too high of an octane can be a bad thing as well. It can cause pre-ignition, which is why Dodge recommends against too high of an octane. Running 91 will probably be fine even on a stock engine (where 89 is recommended), but you are really just wasting money because it doesn't offer any benefit, performancewise.

 

right, when i first read the post it reminded me how a lot of people on the forum were posting about going up in octane ratings and thats basically how it got me on that topic of the higher octane rating, sorry for the confusion!

 

Yeah, I gotta admit, I'm kinda lost on this one too.

Also, I can't see how a clogged EGR, a normal occurrence over time, no matter what octane you use, resulted in a $600 repair bill. Sounds to me like your mechanic kinda "saw you coming".

Although personally, I fail to see how someone can justify NOT spending an extra 20 cents or so a gallon on a $30k+ investment. When a manufacturer "recommends" a certain grade of fuel, you need to just swell up and use it.
The only time I'd consider 87 octane is if the manufacturer states that the engine is specifically designed for 87 and you will get NO benefit from a higher octane fuel.

 

i ran 87 in mine for one summer. then it started running rough and got CELs. took it to the dealer under warranty, and i had predetonation in 2 cylinders, burning holes right thru them calling for an overhaul and teardown. all covered under warranty, but the dealer said running at least 89 in it would prevent it in the future. so i do. too many potential problems tryin to save so little money on 87.

 

the hemis also had problems with the egrs going bad. I had to replace the one on my truck and when i worked at the dodge dealer I replaced tons of them. so the egr problem he had was not actually from the lower octane fuel but you do need to run the higher to keep from detonating your motor. dodge recommends at least 89 octane but 91 will definitely help keep it cleaned out.

 

ive always used regular fuel in my truck, but this reminds me about what my small engine mechanic is telling me...how the carbs in the 2 stroke machines are cloggin up b/c people arent using at LEAST mid grade. i guess its on the same lines with the egr problems.

 

EGR problem can be from lower grade fuel. here's how: Lower octane fuel is very dirty in an engine that is prone to detonation because of the lower grade fuel. Detonation causes lots of unburned fuel and carbon build-up inside the engine. This contributes to faster than usual build-up. Thus why i said higher octane causes less pollutants in an engine because most of the fuel is burnt with very little if anything left behind as deposits.

Babied or *****-footed vehicle can have the same problem. The owner never goes up into the higher rpms often enough to burn or cleanse the engine of all the deposits. A hotter engine is usually a cleaner engine. Usually. I feel (my opinion here)that stock tunes cause more problems than good because of their restrictions with emissions and eagerness to please the EPA. A tuner can solve a lot of these issue's and keep your engine cleaner even when "babying it".

I never baby my vehicles when i drive them, nor do i purposely beat the crap out of them. I keep my mainenance schedule ahead of the manufacturer at all times and haven't had any problem in any vehicles I have ever owned! Ever! Never a tranny problem, never an evgine problem, never been broken down. I am always one step ahead of the manufacturer reccomendations.
Not directly related, but it kinda is...???...lol

 

I also agree with this. i admit, i baby my truck ALOT trying to get good mpg's, and now when i get on it really good, it kinda smokes out the exhaust trying to burn all the excess buildup off.

just recently i have set my hypertech to the 91 setting and running premium fuel. it runs sooo much nicer, better response, etc. hope it helps the buildup problem, plus i know im free n clear of predetonation now as well. My local dealer, after overhauling and rebuilding my engine under warranty, could not stress enough to me that the hemi NEEDS 89 or higher to run without doing damage.

 

My EGR went out around 10K miles, no clogging or what not, the electric solenoid inside it took a crap. When I bought my truck I was told 87 was ok to use so I did till about 9k miles, running mid grade ever 3rd fill up, and that's how I notice she runs a bit smoother on 89 so I stopped using 87. Now I've got a DSP she drinks high grade always.

 

I thank I would contact a lawyer because if dodge did not tell you it is not your falt also I would contact the bbb