89 or 91 octane

[Griebz]

Hey everyone , sorry if this is a re tread . Just wondering if anyone uses 91 instead of the recommended 89 octane ? And are their any long term benefits ?

 

[Hemi395]

Probably not. Anything above 89 on a stock tune isn't going to do much for you. Only reason I ever run 93 is because its pure gas(no ethanol) at one station near me.

 

[APFSDS]

http://www.ramforum.com/f44/octane_gas_you_using-74198/

not to be a ****. i was just reading this thread, too...

 

[Rzrman328]

http://www.ramforum.com/f44/octane_gas_you_using-74198/

.

Yup...this thread should be closed.

 

[Griebz]

I use 89. Heard you see a difference in mileage with 91. I also heard 91 is better for the engine since it burns cleaner

 

[Irrivirsible]

Owners manual says it will do nothing to run premium. Thr 5.7 hemi was designed for 89 octane I guess.

 

[Ramunit]

There is NO benefit from 91 or 93 octane unless there is detonation going on or you have a tune that advances the timing requiring higher octane to avoid pre ignition. 91 burns slower than 87 and isn't any cleaner nor does it necessarily give you better mileage or more power. If a stock truck is tuned from the factory for 89 then run 89, easy as that.

 

[TruckNut]

Only time I run a higher octane than 89 is if the gas supplier is questionable as in Costco or Kroger. Otherwise it's 89.

 

[maple]

I'm running 87 I have a 2015 5.7 should I be running 89?

 

[Graygoose]

I'm running 87 I have a 2015 5.7 should I be running 89?

I would.

Just my $.02

 

[Thatdude596]

I have ran 87 on my 09 hemi and still do

 

[thegrouch97]

Only time I run a higher octane than 89 is if the gas supplier is questionable as in Costco or Kroger. Otherwise it's 89.

Weird I live in Edmonton, Alberta, Canada and costco sells some of the best fuel you can get in town. I say this as an employee of the largest refinery in edmonton. The IOL Strathcona Refinery. Maybe that's unique to here.

 

[Jerry1984]

I'm running 87 I have a 2015 5.7 should I be running 89?

The manual says 89 recommended but 87 is acceptable. I'll find how they have it worded. I run 87 except for when I'm towing I try to run 89.

From manual page 560

5.7L Engines
This engine is designed to meet all emis- sions regulations and provide satisfactory fuel economy and performance when us- ing high quality unleaded gasoline having an octane range of 87 to 89. The manufac-
turer recommends the use of 89 octane for optimum
performance. The use of premium gasoline is not recom- mended, as it will not provide any benefit over regular gasoline in these engines.
Light spark knock at low engine speeds is not harmful to your engine. However, continued heavy spark knock at high speeds can cause damage and immediate service is required. Poor quality gasoline can cause problems such as hard starting, stalling, and hesitations. If you experi- ence these symptoms, try another brand of gasoline before considering service for the vehicle.
Over 40 auto manufacturer’s world wide have issued and endorsed consistent gasoline specifications (the World- wide Fuel Charter, WWFC) which define fuel properties necessary to deliver enhanced emissions, performance, and durability for your vehicle. The manufacturer recom- mends the use of gasolines that meet the WWFC speci- fications, if they are available.

 

[Jmhm17]

Yup...this thread should be closed.

It should be, but it wont..

Instead it will continue on for 17 pages, unlike threads asking legitmate questions. Seems to be the trend around these parts

 

[jasonw]

Only time I run a higher octane than 89 is if the gas supplier is questionable as in Costco or Kroger. Otherwise it's 89.

Costco is good fuel (other than the ethanol they lace into it in my area). Look for the "Top Tier" logo.
Top Tier Gasoline

I do run their 91 for four reasons: 1) I have a tuner. 2) They lace 10% ethanol into it. 3) They do not sell 89, its either 87 or 91. 4) Their 91 with 10% ethanol tends to be cheaper than other stations in the area that have 89 or 91 with 10% ethanol.

 

[arod412]