I have a 2011 dodge challenger R/T with the 5.7 6 speed manual with 6000 miles on it and always used 93 octane gas until my last fill, I used 91 octane because a buddy told me I was wasting money on 93 octane and since the change it seems I have more power, faster start ups even after garaging for days but there is a strange odor coming from exhaust smells like burnt rubber. Does anyone know what this is and is it serious?

I have a 2012 auto with 6,400 miles.... my car calls for 89 octane and the 6spd calls for 91 octane stock from the factory... My car runs best with 91 octane then 93, If I was you I would stick with 91 octane!! has far is the rubber smell I would check to see if you had ran over a plastic bag or some sort because it takes time for the plastic burn off from the exhaust pipes happened to me once... double check to see if you are leaking oil on to your exhaust pipes will also smell... do you change your own oil? if not double check for any leaks specially on the ground!! one more question did you buy the car new? hope this helps!!

Thanks for your help, no I bought it used with 5000 miles on it but its super clean. its been about 700 miles since oil change and I had it done at dodge dealership because I get 6 free ones in the next two years because of my purchase. it is garaged and there are no spots on ground. Its either plastic that I ran over like you said or something like that I was just worried that I ruined the catylitic converters running 93 octane. Thanks for your answer and I am taking your advuce and staying with 91 octance. I know it seems to start easier and honestly seems more powerful than 93 octane. Thanks again

Do you Facebook? if so add me as a friend I can steer you in the right direction about these cars and I also know people who have them that know more then me!! I'm a very passionate car guy willing to help out any way I can!! https://www.facebook.com/profile.php?id=100000737843743

Name is salvatore esposito Eagles fan lol

We are now facebook friends, Salvatore, nice to meet you, thanks for your help and oh yeah even though they are bums GO STEELERS.

I f i where you i'd stick with 93 octane, the 91 is cheaper, but in the combustion chamber, the lower octane gas does not completely burn, and thats why your smelling strong orders. And one other thing,the unused gas will eventually kluge your oxygen senor, and your catalytic converter, and i should not have to tell you how expensive that is!!!!!!!! hope this helps

Thanks for your help rst429, I appreciate you taking time to help me.

Caiaccia1, No Problem, I'm just glad i could help "GO LIONS"

The higher the octane is the slower it burns, my 300C calls for 91 but at times I will mix it with 89 or just use 89 on occasion and it works fine no problems. Bought mine used also and it now has over 100,000 and still runs like it was new. and yes if you use higher octane it will damage the converters and the oxygen sensers and they are H#l& to change, I try to do most of my own work but at 60 Its getting harder to get off the floor. As far as your rubber smell the other poster was right there is nothing that would cause a rubber smell in the engine or exhaust. GOOD LUCK!

Thanks for posting this for me, I appreciate any and all replys to my question and consider it all a huge help for me. Thanks again

Your welcome, just trying to help<,Dave