89 octane recommend, does it really make a difference?

[RebelJC]

Has anyone actually seen an HP and MPG difference enough to negate the price difference from 87 octane? I just did my first fill up and used 89 just because I was headed out of town and wanted to use what was recommended. Not sure if it's going to be worth it.

 

[HeavyMetalHauler]

You won’t see much in the way of performance increase… maybe a mile or two per gallon if you’re lucky.

It’s more to avoid knock.


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[Goatmann]

I do notice a positive few 10ths mpg improvement, I really notice a touch better performance in seat of my pants with 89 over 87.

you have opened a can of worms with this post, sir, though. There will be replies that will agree with my post, many many will not.

 

[theblet]

Idk I’ve been running 87 since I got the truck. All good

 

[redneck]

my gmc says 91 fuel but i run 87 no problem the only time that i notice better mpg is when i go with the rec 90 non eth

 

[DarkKn1ght]

I run mine on 93 as there was still some occasional knock with 89.

 

[redneck]

87 from 7-11 gas station knocks & pings bad in my gmc but if i get it at wawa or piolet their is no problem

 

[BigD]

Owners manual says 89 recommended 87 acceptable. If the manual said 89 required than I would use it. As long as I don't void my warranty using 87, I'm good with it.

 

[RebelJC]

I do notice a positive few 10ths mpg improvement, I really notice a touch better performance in seat of my pants with 89 over 87.

you have opened a can of worms with this post, sir, though. There will be replies that will agree with my post, many many will not.

Agreed, always seems to have mixed reviews from what I've read. But I'm curious still.

 

[RebelJC]

Idk I’ve been running 87 since I got the truck. All good

Do you buy higher quality gas?

 

[RebelJC]

my gmc says 91 fuel but i run 87 no problem the only time that i notice better mpg is when i go with the rec 90 non eth

Ethanol seems to always invite problems.

 

[theblet]

Do you buy higher quality gas?

Murphy USA prob not

 

[JF19Longhorn]

Try to run 89oct.. lately I've been waiting till 1/2 to 1/4 tank left and filling it with 93oct followed by 1/2 tank left and filling with 87oct.. Since 89Oct around here seems to be within $0.10 of 93oct and 87oct is usually a good $0.60 less than that. Technically it saves me some $$$ over the long run and I'm right around 89-90 oct in the tank. Dunno.. seems to make sense to me.

*If I plan on towing I run 93oct for the entire trip. Cheap insurance.

 

[silver billet]

It's interesting that Nissan is now rating their engine's HP/Torque based on octane. It's derated if you use 87. Ram recommends 89. Two examples where higher octane will benefit you, though if you don't work your truck hard you may never notice the difference.

Fuel quality is also important, maybe more so than octane. I run 89 most often, though I've stuck 91 in during the middle of hot summer months when I'm towing my TT, there is far less pinging on 89/91 than on 87.

 

[brian42]

Owner's manual also says to use Top Tier gas.

The octane might make a slight difference in economy (timing adjusted to avoid pinging) but the 'better' Top Tier gas and as close to 0% ethanol will make the most difference IMO.

Even doing the same routine each tank I will fluctuate 1-1.5 mpg overall at fill-up (@ 1/4 tank) so there's no real way to tell how much of an effect there would be if I change.

The first tank was "free" from the dealership when I bought it and I'm sure they went and filled it with the cheapest 87 octane they could find. I think I got around 14 mpg for that first tank but it was also the first few hundred miles of the engine's life so was still getting broken in (I bought the truck with 40 miles on the odometer).

I currently use Costco 91 Octane as it is Top Tier gas and costs about the same as 89 octane anywhere else (sometimes a bit cheaper). The truck is happy so I am happy.

 

[SD Rebel]

Same here, I use 91 Costco, Top Tier fuel, cheaper than most other stations 87 octane.

They say you can use 87 octane, never noticed a difference whatever octane I used, however some folks here have mentioned some light engine knocking when using 87, which the manual says is fine.

That being said, considering the price of the truck, I rather not risk it, just go with ARCO 89 or Costco 91 if I were you.

 

[redneck]

every pump where i live says atleast 10% ethanol unless you get rec 90 but it cost $3.60 pr gal

 

[DarkKn1ght]

every pump where i live says atleast 10% ethanol unless you get rec 90 but it cost $3.60 pr gal

I would definitely get rec 90 when you can.

 

[IvoryHemi]

I use 87 for everyday driving and 89 when towing.

 

[392DCGC]

Has anyone actually seen an HP and MPG difference enough to negate the price difference from 87 octane? I just did my first fill up and used 89 just because I was headed out of town and wanted to use what was recommended. Not sure if it's going to be worth it.

Probably not. I've never noticed a tangible difference. And my mom has run 87 octane in her 2009 Aspen w/ a Hemi for over 300K miles just fine. Data logger may say otherwise, but even in terms of knocking and MPG... my truck runs seemingly the same on 87 as ~90 (93/87 50:50 split). I fill up almost exclusively at Costco with a ~90 octane mix, but filled up entirely with BP 87 this week since I wasn't near Costco and needed gas. Truck sounds and feels absolutely no different. Still, I'll probably run the ~90 octane mix most of the time since Costco fuel is cheaper than the competition (especially their higher octane fuel) and the manual recommends it. Costs me a few bucks more per tank to run higher octane at Costco. They're eeking out almost as many ponies as they can in these relatively dated 5.7 NA Hemi's. If you aren't going to use boost, you have to increase compression and use higher octane fuel to get more power.

Try to run 89oct.. lately I've been waiting till 1/2 to 1/4 tank left and filling it with 93oct followed by 1/2 tank left and filling with 87oct.. Since 89Oct around here seems to be within $0.10 of 93oct and 87oct is usually a good $0.60 less than that. Technically it saves me some $$$ over the long run and I'm right around 89-90 oct in the tank. Dunno.. seems to make sense to me.

*If I plan on towing I run 93oct for the entire trip. Cheap insurance.

Instead of wasting time going to the gas station more often, just fill 50% of your available tank capacity with 93, followed by 87 to top it off (makes sure you get all the 93 octane out of the pump hose that you paid for). If you have a 26 gallon tank, ~13 gallons of 93 followed by ~13 gallons of 87 nets you the same result without having to go to the gas station twice as often. And if you happen to fill up prior to near empty, just do the math in your head of how many gallons needed to fill up, then halve that for 93 and 87 octane. Adds an extra step of paying/pumping twice, but I'll take that over stopping for gas more often...

I would definitely get rec 90 when you can.

Waste of money. It's not a racecar.