I know 89 is recommended on the manual of my D R/T....but dealer says 87 will do.

Please chime in pros and cons of using 87 vs 89. Thanks!

 

87 will give you less performance. The computer will adjust to the lower octane. What your saving (pennies per gallon) won't outweigh the loss of performance that you're expecting from your R/T. People have been known to put in cheap gas when the car REQUIRES mid-grade or even premium, but then turn around and complain the car is junk because they aren't achieving the performance they expected. Chrysler recommends 89 for the HEMI because their performance claims are based on the correct fuel usage. The vehicle will run without harm on 87, but why pay $35k -$50k on a vehicle only to turn around and cheap out on the gas you put into it?

 

I put nothing less then 89, and every 5 tanks i use 93.

 

And what would be your reasoning for using the 93 every 5 tanks?
This should be good

 

Just to see if there is any difference in perfomance. And with out a dyno you cant tell but i just like to do it anyways lol.

Theres really no reason.

 

Well for the future money in your pocket, octane rating has nothing to do with performance. Rather the octane rating is a rating to how much compression and energy it actually takes for the gas to ignite. So lower octane ignites easier, which can cause knocking in older engines. So just save the money and trust me, 93 is not going to give your D more "power" or acceleration, just less money in your pocket unless your car ever calls for it.

 

Thats ok, ive done it with all my other turbo cars so it really doesnt matter to me. Also i dont pay for gas lol....

 

Got it...89 it is. Then here comes the debate...does brand matters? Like mobil/shell/valero/arco? This should be interesting..

 

My company uses mobil, so thats the brand i use. Also exxon because they are the same.

 

No, company does not matter, all companies are all mandated by the same government regulations to produce the same quality gas with the same minimum amount of solvent in the gasoline. The only thing I would say could be differently is by using older gas stations that may not have updated storage tanks. Some of the older gas stations have tanks that are more susceptible to trash and debris getting into the tank. Its all about advertisement and image. If you use a fuel injector cleaner every 3 months it doesn't matter what gas station you use, but like I said that doesn't matter anyways.