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Ok so with certain performance cars I've always believed that you have to put premium gas in the cars. Is this the same with the challengers?
 

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My owners manual states that you must use 91 octane (premium) for R/Ts with the 6 speed, and all SRTS.
 

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Ok so with certain performance cars I've always believed that you have to put premium gas in the cars. Is this the same with the challengers?

Premium is ONLY needed with the SRT 8 model and 5.7L with manual transmission.
The 5.7 Hemi Automatics and 3.6 engines can use 87 but 89 is preferred

3.6L Engine
87 Octane Acceptable - 89 Octane Recommended

5.7L Engine
87 Octane Acceptable - 89 Octane Recommended
5.7L Engine with manual transmission 91 Octane Recommended

6.4L Engine
91 Octane Only or higher
 

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It's my understanding that technically you can get away with not following manufacturers recommenations for premium gas in the 5.7 6sp or 6.1/6.4.

Personally I have never tried that, and I only run premium in my RT 6sp. Basically I wouldn't have bought a performance car if I cared about saving money on gas. Particularly when that savings can come with the cost of reduced performance.
 

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WOW I didnt know this and I have a 6SP Manual. Is this going to mess my car up or anything? I always thought only the SRT takes premium.
 

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WOW I didnt know this and I have a 6SP Manual. Is this going to mess my car up or anything? I always thought only the SRT takes premium.
Naw, I don't think so. Your ECM will adjust accordingly, but you're not getting the best performance/MPG out of your car.
 

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Premium is ONLY needed with the SRT 8 model and 5.7L with manual transmission.
The 5.7 Hemi Automatics and 3.6 engines can use 87 but 89 is preferred

3.6L Engine
87 Octane Acceptable - 89 Octane Recommended

5.7L Engine
87 Octane Acceptable - 89 Octane Recommended
5.7L Engine with manual transmission 91 Octane Recommended

6.4L Engine
91 Octane Only or higher
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+1, this is the gospel, what you decide to do is up to you. Using a lesser octane will negatively affect performance and efficiency due to computer adjustments to avoid engine damage; using higher than ideal octane is a waste of $$.

Also bear in mind that most stations add up to 10% ethanol (sometimes 15%), this is cheaper for them, but less fuel efficient. As to what mpg you sacrifice for paying more for 100% petroleum (no ethanol) only, I can't say.
 

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Naw, I don't think so. Your ECM will adjust accordingly, but you're not getting the best performance/MPG out of your car.
Thanks. I have been wondering why I only get 11.5 mpg. I just bought a 2010 R/T Classic and I have about 1500 miles on it now and been using regualr this whole time. I didnt know it required premium. I wonder if my mpg will get better when I switch.
 

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Thanks. I have been wondering why I only get 11.5 mpg. I just bought a 2010 R/T Classic and I have about 1500 miles on it now and been using regualr this whole time. I didnt know it required premium. I wonder if my mpg will get better when I switch.
You should get a little better mpg with premium. When you use anything less than premium the ECM pulls timing because of the low octane.
 

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I get 22.5 mpg mixed city/hwy on flat roads w/ A/C on averaging 50 mph city/70 hwy.

11.5 likely means you're driving aggressively (which is just groovy if that is what you enjoy, it's an awesome car!). Also, break-in period is recommended for the first 1000 miles or less with recommended altered speed of driving (avoid long trips at constant speed).

Other posters have noted the engine "opening up" after 4-6K miles of driving. Consider a punch-n-coast driving style: heavy pedal on acceleration up to speed (not full throttle), and coasting to the next stop. This also saves your brake components (and likely tire tread) from premature wear.
 

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Thanks man appreciate the info. As for performance is it a noticable difference going from regular to premium?
Yes it should be try a couple of tanks and let us know.

I never tried anything but 93 in the SRTs but in a previous vehicle that had 10.5:1 compression and said it could use 87 octane the performance was terrible. 91 or 93 was like giving it a shot of nitrous (well not quite).
 
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