I've been seeing that 89 octane is recommended in the Hemi but 87 is accepted. Does it really make a difference? I don't see 89 very often where I'm from. Would bottled "octane boosters" be helpful?

 

Oh boy....that's always a contentious subject with Ram drivers.

Best advice: try each your own and see what you think. Run each for at least three full tanks to really know. Track any observations, mpg, perceived power, etc

 

That's about what I was thinking I'd have to do. I'm pretty sceptical about power/performance differences when we're talking 2 octane points. I'm more concerned about the cleanliness of the burn, any adverse affects to the engine and whatnot.

And on the note of cleanliness, do you guys ever do a Seafoam Smoke Show on the Hemi? I've done it to my 98 Grand Cherokee with the 4.0L I6. I know these new Hemis run a lot cleaner than those older engines but I wasn't sure if that's something people still do on these newer engines.

 

Just follow the manual and leave the snake oil in the snake.

 

2012 5.7. I run 87 octane. Have tried 89 a couple times. I'm with Patricklee, can't believe 2 octane points make that much differance. Like I said, tried it twice, i even tried to imagine a differance in mpg, there wasn't any, and power, i didn't feel any. If I don't see or feel a differance i say there isn't a differance and not orth the extra price. Now 93? Seems there should be a differance but i ain't paying the price

 

One theory I have on the recommended 89 octane is due to the PCV circuit. Since the oil being recirculated drops the octane rating of gas and 85 is considered the bare minimum safe octane then 87 could cause power loss and pinging depending on conditions due to the PCV circuit adding the oil back into the intake track altering your octane. This would be especially true in areas where gas is less in demand and sits in tanks for longer. Now when you add a catch can to the mix it removes this oil allowing the octane rating to hold properly and 87 is more viable as a fuel with less chance of being out of tolerance so 89 would not do as much. Most results from the PCV circuit show a possible drop of 3-4 octane max with 2 more normal. So 89 would always be above the minimum and 87 could drop below the safe threshold without the catch can.

 

Interesting... Would you recommend puttting a catch can on or just sticking with 89 then?

Also, one my previous questions, would your shelf variety of bottled "octane booster" be of any use?

 

Thanks wilcon! I've read a heap of stuff about those catch can thingamajig, and that is the first explanation I have read as to what they actually do! So, the recirculating oil reduces gasoline octane? I get it! Now, on to buying a catch can. They are not truck specific are they? Buy one for an'02, it'll work on '14, etc., right?

 

To answer both questions. The Octane Boosters are a band aid fix that may or may not work. They add other things that don't always work like they should with the motor, detergents etc. Better to run 89 or to install a catch can to filter the oil out of the PCV circuit. this maintains the octane and also keeps the intake clean by not dumping the oil mist back into the engine, adding longevity to your motor, keeping horsepower and efficiency higher.

 

Most gas stations around here have 10% ethanol in the 89 octane fuel. The ethanol blend puts a hamper on performance and you burn through it a lot faster hence the poorer gas mileage. I just picked up my 12' ram. Looking forward to better gas mileage than my 01' ram which gets 11-12mpg.