Dodgemech or anyone that has tried 87 and 89 octane in there Magnum RT.
I have the V-8 Hemi engine. What can I expect in I change from 89 octane gas to 87 octane gas. What will fuel economy and performance do? I do average driving. Magnum has 6,000 miles on it and I get 25.5 MPG average interstate driving at 70 MPH with AC on.I have gotten 26.5 MPG a few times when weather was cooler.I have had my Black Magnum RT 9 months now with no problems. I have been rotating the tires every 3000 miles.

Buddy in KY

 

I finally got a chance to take a trip in my ’06 R/T. I have used 87 octane gas since taking delivery. It now has almost 3000 miles on the odometer.

I traveled from northeastern CA to the Elkhorn Mountains in Oregon, a round trip of 839.6 miles on highway US 395 to John Day, then a State highway to Sumpter, OR and back. Elevations from 2000 ft to 6500 ft.
This is a two lane road all the way, varying from high desert to mountain winding roads.
It was hot, so the A/C was in use most of the way. Maybe 10 miles of the trip was city driving.

Whenever I found some straight stretches where I could see far ahead and behind, I did a few WOT’s. A 60 to 100, two 60 to 110, a 60 to 122, and a zero to 110. On the 60 to 122 I let up on the throttle at 122, and it shifted to 5th gear. This surprised me, as I thought it was already in 5th. Never tried to reach max.

My overall MPG for the trip was 24.6. This really caught my attention, as I thought that playing around and driving over the speed limit (CA 65 and OR 55) would put me down to around 17 or 18.

Big complaint…If you open a window and drive at speed there is a terrible pulsation in the cabin. Had to keep windows up and A/C on. Another complaint is the transmission… it is sluggish on shifts, and seems to slip at times.

The thing about the car that impressed me most, was the way it corners on mountain roads. When a sign said SLOW TO 40, I could take the turn at 60 and above. No one could stay with me on the windy roads.

Possibly, 87 octane works ok in the higher elevations. I haven’t been down to sea level yet.

old Bob

 

Sure you can use 87 octane gas in your Hemi, but the computer will sense engine knock and retard timing...........losing you some horsepower.

You won't hear the engine knock, but the computer will.

The 89 octane only costs about $.10 more a gallon, so what are you really saving?

I have used 89 octane gas since I got my RT.

The factory engineers know what the engine needs, so use it.

Bob

 

Flordia Bob, I think you are right. I only drive the Magnum RT an average of 7,500 a year. If I were to change to 87 octane gas I would save less than $50.00 a year,or one tank of gas. If I want to save some money I need to drink less Cokes.The Magnum RT is a fine running machine.

Kentucky Buddy 68 years young

 

What kind of mileage do you R/T guys see when you do mostly city driving? If you have any mods (K&N stuff, etc.) please post that too.

I have a 3.7L Jeep Liberty and see about 16.5mpg city, 21mpg highway--- and when I drive kinda hard in the city I drop to about 15mpg.

Anyone with RWD only Magnums would help also, I'm not sure if I am into AWD.

 

I agree about the knock sensor... your computer will compensate for it. I have never, nor will I ever in the future use less than 92 octane in any car. It just makes sense to prolong the life of the motor and reduce any performance issues down the line.

I know people like to take a yearly look at gas prices, but realistically if you look at each fillup you are only spending an extra $5 or $6 in gas to go with a cleaner burning fuel. That in turn can reduce your maintenance and possibly save you even more money after a few years of driving by taking care of your engine.

 

my little 2.7 gets about 16 no matter what

but on the window down thing, i found that if you put all four down you get a nice breeze inside without being pounded, now with that said at 100 mph it gets a little loud, but at "normal" speeds its great

 

The wind buffeting issue is in the owners manual to reduce this effect i crack another window about an inch. This seems to work great and is whats suggested in the manual.

On my first road trip my wife read me the manual to pass the time. SO i actually remember that one.

 

I use 89 myself normally, once in a while ill use premium. Most of my driving is freeway, even in town. Ive also found that rolling the back windows down and inch or 2 stops most of the wind buffeting. I dont know why Dodge doesnt make the rear side windows open like the Caravan. Just opening from the rear an inch would be great. Would even stop the mild buffeting from open sunroof too. Ive noticed that the little pop up plastic piece in the front of the open sunroof is worthless also, taped it down to see and didnt notice any change at all except it looks tacky as hell.

 

I agree on cracking the rear windows a couple of inches, makes a difference.

A lot of times I will leave the front windows up and just crack the rears open, use the vent feature on the A/C controls. You get good ventalation and no air noise in your face.

As for mileage, my RT never gets less than 17 MPG in the hot Florida humid air, while just city driving. My A/C goes on in mid May and stays on until mid October, that is the usual hot season here in North Central Florida.

BTW, regular gasoline hit $3.00 a gallon here.

Bob