People with gas mileage issues

[smashweights]

That's true...87 is acceptable when 89 is not available but my coworker has a 2016 Hemi Ram and after a year of using 87 octane he's getting the cylinder knock and even some lifter tick now. Smh....

Per the manual:
"
This engine is designed to meet all emissions regula-
tions and provide satisfactory fuel economy and
performance when using high-quality unleaded
gasoline having an octane range of 87 to 89 as specified by
the (R+M)/2 method. The use of 89 octane “Plus” gasoline is
recommended for optimum performance and fuel economy.
While operating on gasoline with an octane number of 87,
hearing a light knocking sound from the engine is not a cause
for concern. However, if the engine is heard making a heavy
knocking sound, see your dealer immediately. Use of gaso-
line with an octane number lower than 87 can cause engine
failure and may void or not be covered by the New Vehicle Limited Warranty."

 

[PowerJrod]

Per the manual:
"
This engine is designed to meet all emissions regula-
tions and provide satisfactory fuel economy and
performance when using high-quality unleaded
gasoline having an octane range of 87 to 89 as specified by
the (R+M)/2 method. The use of 89 octane “Plus” gasoline is
recommended for optimum performance and fuel economy.
While operating on gasoline with an octane number of 87,
hearing a light knocking sound from the engine is not a cause
for concern. However, if the engine is heard making a heavy
knocking sound, see your dealer immediately. Use of gaso-
line with an octane number lower than 87 can cause engine
failure and may void or not be covered by the New Vehicle Limited Warranty."

Exactly....87 octane can cause heavy cylinder knocking (otherwise the manual wouldn't mention knocking at all). And my coworkers engine now has a permanent knocking sound even now that he's using 89 octane since last week. No point In risking it just to save..what? 10-20 cents per gallon..? Nope.

 

[Duran]

Exactly....87 octane can cause heavy cylinder knocking (otherwise the manual wouldn't mention knocking at all). And my coworkers engine now has a permanent knocking sound even now that he's using 89 octane since last week. No point In risking it just to save..what? 10-20 cents per gallon..? Nope.

How long was her running 87 to produce a permanent knock

 

[Duran]

How long was her running 87 to produce a permanent knock

I ran 87 for just a couple months and i made the switch to 89

 

[Dusty1948]

I ran 87 octane fuel in both of my 4th gens and never heard any pinging or 'knock' caused by fuel, and that's driving in mixed topography (western New York state). Now that was with both vehicles running 3.92 gearsets. With those axle ratios it would be the least likely to experience fuel knock. My 5th gen has the 3.21 axle and I've yet to heard any fuel knock on 87.

Keep in mind that altitude and fuel quality at the pump can affect individual experiences. I ran car wash gasoline for years with my first two Rams, but then discovered other issues due to a shift in fuel quality. I've since switched to Mobil or Sunoco fuels even though they are more expensive. And by the way, around here the difference between 87 and 89 octane can be 45 cents or more.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 03 June 2018. Now at: 037913 miles.

 

[PowerJrod]

How long was her running 87 to produce a permanent knock

It was close to a year because he wanted to be cheap. He brought it into the service center this past Friday and they confirmed that it was low grade/low octane fuel. End of the day...the year using 87 octane he only saved like $35 and he's out of his warranty. If his 4th did this I have no doubt the 5th gens will be more susceptible to it... especially with Etorque.

 

[davidajpritchard]

Happy with mine so far

Sent from my SM-N960W using Tapatalk

 

[Duran]

It was close to a year because he wanted to be cheap. He brought it into the service center this past Friday and they confirmed that it was low grade/low octane fuel. End of the day...the year using 87 octane he only saved like $35 and he's out of his warranty. If his 4th did this I have no doubt the 5th gens will be more susceptible to it... especially with Etorque.

I agree completley. 35 bucks is not worth it nor is any amount for the performance and longevity of your truck

 

[TheMadDutchDude]

I run mine with 93 all the time because it’s only the sake of $5 between full tanks. It’s either 87 or 93 from Costco. 93 is the same price as 87 everywhere else, so I consider it like I’m paying for 87 but know that my motor will thank me later. I also like to stomp on the gas to let that sweet, sweet Borla noise burble down the road.

 

[Jako]

I run mine with 93 all the time because it’s only the sake of $5 between full tanks. It’s either 87 or 93 from Costco. 93 is the same price as 87 everywhere else, so I consider it like I’m paying for 87 but know that my motor will thank me later. I also like to stomp on the gas to let that sweet, sweet Borla noise burble down the road.

I do Costco but I do 1/3 93 octane and 2/3 87 octane blend. Always start with the 93 octane so I flush out the 93 from the pump line with the 87 octane. 30 to 50 cents difference between octanes. Doing the "blend" at a NJ Costco versus 89 at my NY local service station is probably close to 50 cents.
I do like to support my local station and I do but I also know the Costco gas is always being refreshed, not sure of the 89 octane at my local station. Today filled up with 87 at the local station for a 150 mile round trip tomorrow in which I will fill up with 93 at Costco to get my octane back to 89.
Costco and my local (Citgo) are both Top Tier gas certified.
To get how many gallons (1/3 2/3) I do quick/close enough calculations off my mpg meter and gas tank miles traveled. I always fill up the tank.
I have averaged 16.69 mpg for 19,266 miles for 1,154 gallons of gas, .30/gal is a $346.30 savings and .50/gal is $577.00 savings. November 24th will be the Rams 2 year anniversary, $3.80 to $6.34 savings per week.

 

[Shives]

My truck started in the 400, now down in the 300,s if lucky for mpg on a full tank to empty. So annoying

 

[PowerJrod]

My truck started in the 400, now down in the 300,s if lucky for mpg on a full tank to empty. So annoying

Ouch. My estimated is around 500 miles...hemi Etorque with 80% highway. Honestly...I'll use 91 octane from Arco and I notice better gas mileage and just runs a little better ...that's only in the high heat during summer though

 

[Willwork4truck]

Dont want to beat this to death however on my recent longer hiway trip, my 5.7 with 3.21’s did ping/knock on 87 with easy acceleration. I try to mix the tanks but cant always. Have to break the “look for the cheaper gas” routine.

 

[smashweights]

Exactly....87 octane can cause heavy cylinder knocking (otherwise the manual wouldn't mention knocking at all). And my coworkers engine now has a permanent knocking sound even now that he's using 89 octane since last week. No point In risking it just to save..what? 10-20 cents per gallon..? Nope.

It was close to a year because he wanted to be cheap. He brought it into the service center this past Friday and they confirmed that it was low grade/low octane fuel. End of the day...the year using 87 octane he only saved like $35 and he's out of his warranty. If his 4th did this I have no doubt the 5th gens will be more susceptible to it... especially with Etorque.

Why would eTorque have any impact on fuel detonation?

The manual isn't stating 87 can cause heavy knocking, it's stating that heavy knock is not expected and abnormal and should be investigated immediately. many other hemis (6.4, 6.2 etc) state they "require" 91 octane and has the exact same knock paragraph even when using the required 91 octane. That would mean even using required premium in those engines would lead to heavy knocking?

Also, for fun, I pulled a few random owners manuals for cars with the 5.7 hemi of various years going back to it's introduction and all of them (Durango, charger, Ram, etc) have this same verbiage. I'd find it very hard to believe that short term use (1 year) of an "acceptable" octane rating in the manual would cause consistent issues in an engine they sell millions of such that over 17 years of replacing engines under warranty that FCA wouldn't bother just changing "recommended" to "required" in the manual to save millions of dollars in warranty repairs.

YMMV and your buddy maybe really did have an issue from running 2 octane too low for only 12 months but I highly doubt it's even remotely a common problem given the implications for the company...

 

[PowerJrod]

Why would eTorque have any impact on fuel detonation?

The manual isn't stating 87 can cause heavy knocking, it's stating that heavy knock is not expected and abnormal and should be investigated immediately. many other hemis (6.4, 6.2 etc) state they "require" 91 octane and has the exact same knock paragraph even when using the required 91 octane. That would mean even using required premium in those engines would lead to heavy knocking?

Also, for fun, I pulled a few random owners manuals for cars with the 5.7 hemi of various years going back to it's introduction and all of them (Durango, charger, Ram, etc) have this same verbiage. I'd find it very hard to believe that short term use (1 year) of an "acceptable" octane rating in the manual would cause consistent issues in an engine they sell millions of such that over 17 years of replacing engines under warranty that FCA wouldn't bother just changing "recommended" to "required" in the manual to save millions of dollars in warranty repairs.

YMMV and your buddy maybe really did have an issue from running 2 octane too low for only 12 months but I highly doubt it's even remotely a common problem given the implications for the company...

Being doubtful doesn't replace a service techs findings and conclusion lol. It's true that the manuals say if 89 isn't available then 87 is acceptable. But you have to understand that verbage is very different from saying you can run 87 octane all of the time, right?
As far as the Etorque go....it incorporates start/Stop ..so every time the engine kicks back on...you're re-sparking and burning that same initial fuel...whether it's 87, 89, 91, etc... hope I'm making sense here

 

[smashweights]

It's true that the manuals say if 89 isn't available then 87 is acceptable. But you have to understand that verbage is very different from saying you can run 87 octane all of the time, right?

This is where you're mistaken. No manual from the introduction of the 5.7L Hemi in 2003 to my 2019 says what you claim it does. It's very clear:

"This engine is designed to meet all emissions regulations and provide satisfactory fuel economy and performance when using high-quality unleaded gasoline having an octane range of 87 to 89 as specified by the(R+M)/2 method."

There is no implication anywhere that 87 is only acceptable temporarily when you can't find 89.

Even Ford uses nearly identical verbiage in the 2019 F150 manual stating minimum 87 but 91+ recommended for optimum performance and that light knocking is normal and heavy knocking should see dealer immediately.

As I said, it's possible your coworker did have knock related damage, perhaps a bad knock sensor and the computer didn't compensate for the octane change, but my point remains if FCA had any indication over the last 17 years that 87 octane could cause that all they have to do is change a line in the manual and they're off the hook for repairs. They'd be taking a huge risk implying that then warranty the powertain for 5-10y/100k miles especially when other Hemi engines clearly state "required" octanes

 

[Dusty1948]

This is where you're mistaken. No manual from the introduction of the 5.7L Hemi in 2003 to my 2019 says what you claim it does. It's very clear:

"This engine is designed to meet all emissions regulations and provide satisfactory fuel economy and performance when using high-quality unleaded gasoline having an octane range of 87 to 89 as specified by the(R+M)/2 method."

There is no implication anywhere that 87 is only acceptable temporarily when you can't find 89.

As I said, it's possible your coworker did have knock related damage, but my point remains if FCA had any indication over the last 17 years that 87 octane could cause that all they have to do is change a line in the manual and they're off the hook for repairs. They'd be taking a huge risk implying that then warranty the powertain for 5-10y/100k miles especially when other Hemi engines clearly state "required" octanes

Even Ford uses nearly identical verbiage in the 2019 F150 manual stating minimum 87 but 91+ recommended for optimum performance and that light knocking is normal and heavy knocking should see dealer immediately.

Smashweights is correct, the fuel specification is emphatically stated and conveys that fuel between 87 and 91 octane can be used and still meet warranty.

There is an element in this discussion that has been missed. Like any engine manufacturer I can think of, engine designers employ a device called a Knock Sensor. This is a piezoelectrical component used to determine high frequency sound generated by premature detonation. When an engine is first started the timing algorithm starts at maximum timing advance in the PCM map. As soon as knock is detected by the sensor, the PCM algorithm shifts to retard the ignition timing. This can be done in steps, so if the first retard algorithm still produces knock the PCM will continue to retard the ignition timing.

If the subjects vehicle was still knocking on 87 octane it's possible that the knock sensor or the PCM was not working as designed. Without going back in this thread I'm not sure how it was determined that incorrect fuel caused engine damage. If it was, did a technician check the knock sensor circuit? And exactly how bad was this knock? I've known a number of people who have owned Hemi motors and I've never heard any of them complain about pinging or knock caused by fuel quality. I do know that 85 octane is available in some parts of the country, and I'm sure it would be among the least expensive. That low of octane would probably be outside the range of engine timing management.

Best regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 03 June 2018. Now at: 037950 miles.

 

[PowerJrod]

This is where you're mistaken. No manual from the introduction of the 5.7L Hemi in 2003 to my 2019 says what you claim it does. It's very clear:

"This engine is designed to meet all emissions regulations and provide satisfactory fuel economy and performance when using high-quality unleaded gasoline having an octane range of 87 to 89 as specified by the(R+M)/2 method."

There is no implication anywhere that 87 is only acceptable temporarily when you can't find 89.

Even Ford uses nearly identical verbiage in the 2019 F150 manual stating minimum 87 but 91+ recommended for optimum performance and that light knocking is normal and heavy knocking should see dealer immediately.

As I said, it's possible your coworker did have knock related damage, perhaps a bad knock sensor and the computer didn't compensate for the octane change, but my point remains if FCA had any indication over the last 17 years that 87 octane could cause that all they have to do is change a line in the manual and they're off the hook for repairs. They'd be taking a huge risk implying that then warranty the powertain for 5-10y/100k miles especially when other Hemi engines clearly state "required" octanes

Try again. It's in the manual. Not the part where there's the giant number 89 or 87. Keep reading a few pages down. It says 87 is "acceptable". That doesn't mean you should use it continuously.
The other thing that might have contributed though...was him not using TOP TIER gas...even the manual states to use TOP TIER. You two can interpret how ever you want...but I know how to read between the lines. Like I said...service tech already confirmed it to be low quality gas with not enough octane....good luck trying to argue with a RAM service tech lol.

 

[smashweights]

Major corporations do not put out recommendations for safe operation that requires you to read between the lines. Anything shy of explicitly stating you cannot use it continuously opens FCA up to legal repercussions in the event of failure. Not sure how else to convince you otherwise. Best of luck!

 

[UnloosedChewtoy]

Another wrench to throw in here (sorry if it was discussed earlier and I missed it), sometimes the gas companies cheat until they get caught cheating.

A year or two ago, we had an incident in my area (south eastern South Dakota) where one of the major gas distributors was caught putting 85 octane into 87 octane tanks, and had been doing it for a little while.
The western part of South Dakota is right at the cut-off elevation where, theoretically, you can start using 85 octane instead of 87, so it was easily available to the distributor.
They claimed it was to avoid shortages (yeah huh, sure it was), but couldn't provide reasoning as to why they didn't tell anyone outside their company. They were fined, if I remember correctly, and had to stop doing it.

So you may sometimes think you're using 87, when you're actually using 85. Whereas if they happen to cheat on 89/91/93 and go down to the next octane level, you're still getting 87 or higher.

Also, ethanol hurts. I've said it before, I'll mention it again; my 2014 with the 5.7 seemed to like 87 octane with no ethanol better than 89 or 91 with 10% ethanol. Usually saw a couple MPG bump in highway driving. I deal with it, Costco in my area only sells 10% ethanol fuel, and get 91.