5.7 Hemi Fuel Grade

[DTN]

I'm on my 2nd tank now (using 89 octane) but with the manual stating that the 5.7L can run on 87 octane (89 recommended) I was curious if other members have used 87 and if they have experienced any issues with it?

 

[bskubon]

I use 87 and have noticed no problems

 

[wvinson]

Mine knocks on hard acceleration on 87 or 93 -- doesn't matter which.

 

[Richard320]

89 octane recommend, does it really make a difference?

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.

5thgenrams.com

 

[RickWaz]

No prob's when I've used 87. I'll use 89 when it's available, and when not 87 (or sometimes 93).

 

[The Critic]

HEMI definitely pulls timing on 87 vs 89. I have personally noticed a small difference in responsiveness with 87 but the MPG difference is too close to confirm.

The cost of 89 is reasonable if you fill at Costco. I just do my own 50/50 mix of 87 and 91 at the pump (in two separate transactions); you just have to do some quick math before each fill.

 

[Reverse]

Our Rams will definitely knock when accelerating hard on 87. I usually get 87 though, and take it easy. I do get 93 at Costco occasionally (since they don't have 89 and 93 is fairly cheap) and that does make a difference. Truck feels more powerful. However, as far as fuel efficiency I don't see much difference.

 

[BobK]

I have only used 87 since I got it, runs totally smooth. Got 3500 miles on it now. I believe the manual said 89 is recommended if towing/hauling which I rarely do.

 

[mikeru82]

I gotta admit, I didn't even pay attention to the recommended octane when I first bought my truck. The dealership I bought from always includes a full tank of fuel with a new vehicle sale. I drove the sales rep to the gas station and they filled it with 87 octane. So that's what I used for the first year I owned my current truck. I never experienced any pinging or decreased performance for that year. I switched to 89 octane about six months ago after seeing that's the recommended octane, and the truck runs and drives exactly the same to me as it did on the 87. I'd never know whether it had 87 or 89 if I didn't put it in myself. So I'm going back to 87 octane. No sense paying more for gas if it doesn't make any discernible difference for me. Maybe if I towed or hauled anything that weighed more than a couple hundred pounds I might go with 89. Elevation can also make a difference. I don't live in the mountains, but we're over 2k feet above sea level here, if that makes any difference.

 

[UnloosedChewtoy]

If our Costco didn't add 10% ethanol to everything, I'd be doing a mix of 91 and 87 (the two octanes offered at the Costco here). However, they do not have an ethanol-free option, so I always use 91.

Have not experimented yet with the 2020, but my 2014 Hemi always ran better on 87 ethanol free gas than 89/90/91 with 10%. A lot of places out here though, you don't get a choice without going out of your way. By "ran better", I simply mean it got better MPG. I did not really notice any differences in drivability/performance.

I will never run 87 with 10% (or higher ethanol) unless there are no other options within my fuel tank range.

 

[tones2SS]

Mine knocks on hard acceleration on 87 or 93 -- doesn't matter which.

Wow, on the 93 octane as well?
What brand gasoline? That could be the problem.

 

[BowDown]

On my previous truck, 87 cost me about 1-1.5 mpg consistently.
On 87 octane, my 26 gallon (23 usable) got 300 miles per tank. Using 91, the same 23 gallons yielded 320 miles per tank.
87 ran fine, no knocking, just fewer mpg. My opinion, 87 octane calls for a reduction in ignition timing reducing low speed torque. This causes you to use more throttle accelerating and reduces fuel mileage.

When I switched back to 89, the lost 20 miles a tank returned.
In this truck, I use 93 because I buy fuel at Costco (top tier gas), 93 at Costco is usage same or a couple cents different from 89 at other stations

 

[paulmarsh22]

I fill up at either Sam's or Costco so they only have 87 or 93. I've ran both and haven't noticed much of a difference. I feel like there is a slight power decrease when running 87 but it also seemed like I got better fuel economy running 87 vs 93. I tested two tanks running both grades over 300 miles on the same drive and got roughly 1mpg better with 87. Granted, outside temp and wind could've played a small factor as well. But for the price of 93 at the wholesale pumps, I'd rather run the higher grade and be done with it.

 

[yankeefan31569]

last couple tanks i been using 87 going back to 89 motor pings and is jumpy and a bit more noisy on cold morning start ups..on 87

 

[SD Rebel]

I have only used 87 since I got it, runs totally smooth. Got 3500 miles on it now. I believe the manual said 89 is recommended if towing/hauling which I rarely do.

Actually that's what Ford's Ecoboost motors say, 87 but 91 for towing.

RAM states 89 for "optimum performance & fuel economy". I honestly don't notice a difference in performance or mpg with 87, 89 or 91. Since I go to Costco, I just use 91 since it's cheaper than other stations 87.

 

[wallyuwl]

Around here all the ethanol premium is 93, and non ethanol premium (about half the gas stations have it) is 91. I usually get the 91 because of the better gas mileage of 1.5 to 2 mpg vs ethanol. Once in a while I will get Fleet Farm no ethanol 88. Higher octane definitely helps the hemi in performance.

 

[NoExpert]

I use 87 and have noticed no problems

+1 here

 

[wvinson]

Wow, on the 93 octane as well?
What brand gasoline? That could be the problem.

IT was shell -- so I think it's an engine issue.