Are you running 87 or 89 octane fuel?

manual recommends 89 for "optimal performance" yet says high quality 87 will work.

- Dan M

When I first bought my R/T I was using 87. When I changed to 89, I noticed a little better performance, with no MPG change.

running 89... that is what i was told is recommended.. plus the cost is minimal...

89 here, unless I get the oddball station that only has regular 87 or premium, in which I get 87.

I've been running 87 octane consistantly with no ill effects. As long as theres no knocking in the engine, running a higher octane doesn't do anything, other than cost you more money.

Even if you increase gas mileage by using higher octane, I think the increase would/will be minimal. I'm not even sure I trust that the gas stations are really giving me 89 octane anyways, since every once in awhile they have a "sale" where 87 and 89 octane cost the exact same.

At any rate octane rating is the amount of fuel that can be compressed before it spontaneously ignites. 87 octane can handle the least amount, 91 (or higher) would be the most amount. If the gas ignites from compression rather than the spark plug igniting it you get knocking, which is can be bad for your engine.

I've been running 87 octane consistantly with no ill effects. As long as theres no knocking in the engine, running a higher octane doesn't do anything, other than cost you more money.

Even if you increase gas mileage by using higher octane, I think the increase would/will be minimal. I'm not even sure I trust that the gas stations are really giving me 89 octane anyways, since every once in awhile they have a "sale" where 87 and 89 octane cost the exact same.

At any rate octane rating is the amount of fuel that can be compressed before it spontaneously ignites. 87 octane can handle the least amount, 91 (or higher) would be the most amount. If the gas ignites from compression rather than the spark plug igniting it you get knocking, which is can be bad for your engine.

Very good info., and so true about knocking being bad for your engine. But,.....well...umm...I'll just shut my big mouth.

Very good info., and so true about knocking being bad for your engine. But,.....well...umm...I'll just shut my big mouth.


Lol, what? I hope you didn't take any offense to my post...I always look forward to hearing different points of view. Its just that this one is constantly being beat to death in another forum that I am a member of, for motorcycles. Seems to come up every few days.

I guess we haven't beat it to death here yet, so lets hear your pov, so we can learn...:)

hey guys all great information. But check your manuels for the Octane they recomend. Some of the books I have looked in lately actually tell you not to run anything above 89 Octane or it could damage the engine. I don't know how true this is but hey. I don't want to chance blowing my engine!!!

Its just that this one is constantly being beat to death in another forum that I am a member of, for motorcycles

:DSure enough it does. Once a week on the bike forums I'm on. My Firebird had such a HUGE CC head on it before I milled it down and the stock pistons so deep in the holes I'm pretty sure it would run on water. LOL.

What bike are you sporting?

To answer the question.........87.

:DSure enough it does. Once a week on the bike forums I'm on. My Firebird had such a HUGE CC head on it before I milled it down and the stock pistons so deep in the holes I'm pretty sure it would run on water. LOL.

What bike are you sporting?

To answer the question.........87.


'05 ZX-6R....don't get to ride enough...I think I have 4400 miles in the 2 years i've owned it!

'05 ZX-6R....don't get to ride enough...I think I have 4400 miles in the 2 years i've owned it!

Nice bike. You're right......you need to make more time to ride it. :gy:

Lol, what? I hope you didn't take any offense to my post...I always look forward to hearing different points of view. Its just that this one is constantly being beat to death in another forum that I am a member of, for motorcycles. Seems to come up every few days.

I guess we haven't beat it to death here yet, so lets hear your pov, so we can learn...:)

No, I have no problem with your post. At my age I do not let things bother me.

Nice bike. You're right......you need to make more time to ride it. :gy:


I just need to sell it. Its fun but I have too many bills already :/

my manual sez 87-89, buddy also has an 06 charger & his sez the same....maybe canada has something different, dunno.

hey guys all great information. But check your manuels for the Octane they recomend. Some of the books I have looked in lately actually tell you not to run anything above 89 Octane or it could damage the engine. I don't know how true this is but hey. I don't want to chance blowing my engine!!!

To go along with the gas mileage thread, I've fueled up with 89 octane this past tank. So far, my gas mileage seems to be suffering for it. But it has been alot colder lately which means more warm up and tire spinning in slick weather and lower average tire pressure, so that may have something to do with it. That and if it takes a while for the computer to adjust to a different octane gas (which i don't think it matters, but who knows?) . So I am going to run at least 1 more tank of 89 after this one and see what happens, and if the cold weather holds I'll switch back to 87 and go from there.

Its all very interesting to me :)

Thanks for the information avengerRT. Let us know how things go.

if anyone's curious, i just checked & it sez 12.8 mpg, and this is no typo. but, in the car's defense, along with the reasons already noted above, i warm it up a good ten minutes before going anywhere, pretty well always start off with the seat/coffee warmers on (definitely in the mornings), i haven't reset it since i bought it (9200 km ago) and i'm a smoker so keep the sunroof at least 1/3 the way open all the time so the heater's going constantly. there's lots drawing off the car, so actually i'm not too surprised, not to mention the stereo is always cranked (i really like having more watts than HP though). i haven't plugged it in yet either, even when it hit -28C in the mornings for a bit. still happy with it tho.

oh ya, i use 89 if they have it, 87 if they don't.

Is there any risk of using 93 aside from the price?

using 93 octane burns hotter and if the engine is not built to handle the extra heat you could damage alot. as said earlier in this thread, check the Manuel and it will outline the highest octane you can run safely, which I believe is 89. I may be wrong though. I have been filling with 89 since I bought my avenger so not sure if there is much of a difference with lower octane. I just know that 89 burns a bit cleaner... good enough for me.

In one of Dodge's news conferences they announced that all models of the avengers would be built to handle low octane fuel with no ill side effects. it used to be that low octane fuel would cause build up in the cylinders and would eventually need to be cleaned out with an additive. But newer model cars have worked around this and now do not suffer from the build up (or so they say) but none the less, dodge says no harm running lower octane fuel.

I run 87 and it seems to work just fine...Car and Driver magazine wasn't kidding when they said the R/T got SUV like gas milage...I've filled this thing up more...Oh well...It's a fun car!!

I get around 260-270 miles per tank and tend to only put in around 14.5 gallons each fill up by the time the light comes on. Considering my V8 Dakota I was putting in $60ish per tank/280 miles to the tank.. I won't be complaining.

I run 87 and it seems to work just fine...Car and Driver magazine wasn't kidding when they said the R/T got SUV like gas milage...I've filled this thing up more...Oh well...It's a fun car!!


I dunno....my wifes suv gets 12-15 mpg....my RT gets way more than that! hehe

I've been getting 15 - 16 mpg with the AWD...I get 14 - 15 with my Avalanche...But I never can seem to keep my foot out of either of them?:4-dontknow: :4-looney:

I am getting around 24 on my AWD

I'm getting 15-16 in my 02 Dakota QC 4x4 and 21.5-24.5 in my 08 Avenger R/T. I've been using the remote start a lot lately.

yesterday 22F on way in, 34F on way home
today was 18 on way in

- Dan M

The gas mileage has been disappointing me. On the highway its nice but I'm getting 15-16 city. I was looking around checking out all other V6 models and I noticed a lot of cars give out more hp and get better mpg. My fathers Charger R/T gets around the same mpg. Almost 1200 miles on it, praying it goes up.

The gas mileage has been disappointing me. On the highway its nice but I'm getting 15-16 city. I was looking around checking out all other V6 models and I noticed a lot of cars give out more hp and get better mpg. My fathers Charger R/T gets around the same mpg. Almost 1200 miles on it, praying it goes up.

If you want a true test with your fathers charger, switch with him for a tank of gas. Then see. Because everyone has a different style of driving. Also, are you using the numbers from the evic or the numbers from calculating? The evic is less than consistant and far from accurate in my opinion. Although I've noticed that it gets a little better if you never reset it.

Don't worry about the HP rating of other cars.. Could be high HP but doesn't mean its faster. Keep in mind you have the R/T version.. not something designed to haul heavy weights. Plus the gear ratios are designed differently.

Ok I'm running 87 Octane and went to Greensboro for Christmas. On the way down I took my time and thier wasn't much traffic while I was on the road. I got 28.4 MPG. ON the way back I had alot of traffic to deal with and my mileage dropped to 19.6 MPG. Lots of speed up and slow down. If I take an average of all the tank fulls I am getting a combined mileage of around 24 to 26 MPG. I am very Happy with this considering it is a 2.7L V6 and I was driving a '03 Neon(2.0L 4cyl.) and got close to the same gas mileage.

If you want a true test with your fathers charger, switch with him for a tank of gas. Then see. Because everyone has a different style of driving. Also, are you using the numbers from the evic or the numbers from calculating? The evic is less than consistant and far from accurate in my opinion. Although I've noticed that it gets a little better if you never reset it.

I'm using the evic. But I'll try a legit calculation my next fill up.

I'm using the evic. But I'll try a legit calculation my next fill up.

Then that may make sense. Guess we will see with the next fill up. My evic constantly reads anywhere from 18-19 mpg and when I calculate the actual mileage, I actually calculate 20-21 mpg. And I deal with a lot of stop and go type traffic.

I haven't "reset" the evic in months. When I was resetting the evic, it seemed to show worse mileage, and not really correct itself (as in get back to 17-18 mpg) until the next fuelup. Then I would reset it and start the process over. So I've stopped resetting it and it seems to be better, but still not correct.

Then again, the fuel light is supposed to come on when the car has 2 gallons left. Mine comes on really early, and I usually have 2 gallons left even after the gauge hits the red line at the bottom. So I've just learned to compensate. Basically since I know I get about 20 mpg on average, when it hits red I got about 40 miles max before I get to the gas station. Of course I usually have .5 or more gallons left. I can say that I will usually get 340 miles to the tank, so thats what I shoot for on the trip computer.

I use 88 octane, which is "mid-grade" here in the mountain west. Our options at the pumps here are 86, 88, and 91.