Anyone switched to 87 octane?

[CheechDogg.0n37s]

Both of ours has 10% ethanol mandated by state law, via agrigiant bribery .

There are nonoxy 91 pumps dedicated to small engines, but nobody enforces use compliance.
I'll try the 91/10 blend. We don't need to add supplemental alcohol in winter to prevent gas line moisture freeze up.

So more than likely, your truck won't benefit much from using 91 because of the blend MPGs wise ...but performance wise it should ...

 

[ram1500rsm]

I've been running 91 octane since 2018 when i bought the truck and put my own HPtuners tune in it. A few months ago i switched to 87 octane and the factory tune when gas went to $6-$7 range under the expectation it was going to help with the $140-$150 full tanks every 2 days. That didn't help much if anything Lol and i went back to my tune with 91 octane. What really really helped was me buying a 2022 Kia Rio S to solve the issue with the 2 day fill ups and inmediatly we started enjoying $40-$50 fill ups once every week .

The Kia is the boring DD and that one will remain exactly what i bought it for, A to B cheap transportation, if gas goes back to $3 fill ups will be $24-$27 full tank, 10 years/100k miles warranty with 5 years/60k miles road assistance AND i can fill her up full anywhere in USA at literally every single corner in under 5 minutes and get me 490 miles range hwy, 390 miles city.

The truck is still our family long hauler and overland family rig and anything else in between than our other 2 vehicles are not as comfortable/capable of doing.

 

[Jeepwalker]

BTW guys, Per my previous scanner timing images, I attempted to pull down a scan going up a hill and reading LT Timing ...but my scanner doesn't list LT timing, only ST. (is there another name -- Snap-on)? I guess it wouldnt hurt to perform a timing test going up a long hill as it is, I'll do that tomorrow.

 

[Hemi395]

BTW guys, Per my previous scanner timing images, I attempted to pull down a scan going up a hill and reading LT Timing ...but my scanner doesn't list LT timing, only ST. (is there another name -- Snap-on)? I guess it wouldnt hurt to perform a timing test going up a long hill as it is, I'll do that tomorrow.

Yeah some scanners don't see the LT pid unfortunately

 

[CAGEYAR]

I used Plus exclusively per the manual until I got infected with Bidenvid 5.
$5 was the threshold to go to 87 octane.
FJB

 

[Jeepwalker]

Ok, guys, lets try this again. Help me interpret what do you see here. I'll just include all the images in this post so people don't have to flip back to the earlier posts. The bold numbers to the left of each graph are the real-time readings which change a bit depending on micro-changes in throttle. The red circles are the range. Tests 1-2 are flat driving ~55-60mph. The last image was near the top of a long, pretty steep hill (~50mph). The red box in Test 3 is the whole hill section. The Spark Advance numbers (bold) genarally ranged from as low as 12.5 to 24 with 90 octane, but 14-16 was a middle range I was observing the most (up the hill and flat driving). I wish I took a hill-test snapshot when I had 87 in the tank but unfortunately I didn't. MDS was on during this test. Obviously these aren't controlled or scientific. But any thoughts or reactions you can glean from these graphs ...from the guys who know more about the fine art of timing/tuning than me?

The overall summary is, yep! I can tell my truck has more 'pep' with the higher octane. Sounds like others have the same experience. Haven't done tank-to-tank mileage tests. 91 Octane runs about .90-$1 more per gallon (than 87) around here, which is quite a bit. Costco sells 93 Oct for ~.90 more/gal. Thanks

 

[HEMIMANN]

@Jeepwalker - thanks again for doing another test and sharing with us.

Yeah, the uphill data with 90 octane isn't much for comparison since the engine load profile is so different from the 87 octane and 89 octane data. Would be nice to see the 91 octane with same alcohol content as the lower octanes on the same load profile (presume flat road). But you've done enough - we know for sure 89 octane spark advance is real, or I should say lack of spark re*tarding, since the 89 octane spark advance timing is the default setting.

Good stuff!

 

[Wild one]

Does the Fuel You Choose Matter? | Engine Masters | MotorTrend

Does fuel really matter for your engine? Watch as the Engine Masters team takes a scientific look at just how much power and performance are produced by diff...

www.youtube.com

 

[HEMIMANN]

How the hell did I miss this episode?

Anyway, I watched, and am a tad confused. So they took the Chevy LS 6.2 and ran it with a bunch of different octane gasolines, and there was miniscule difference in torque, AND ignition timing, AND AFR ratio.

Well, wait a minute - we haven't been discussing boosting the Hemi or camming it, or increasing compression either - BUT - we have been talking about advancing ignition timing with increasing gasoline octane rating because, up to a point, this yields more torque and power from a STOCK engine.

Yet, these guys kept saying their engine "liked" the same ignition timing regardless of gasoline octane rating. Huh??? Are they saying they can't advance beyond 29 degrees BTDC because (1) they don't have a timing tool (2) that's as advanced as the engine can take on any octane?

This episode is VERY misleading for engine enthusiasts. It seems it's made for the average slob to prove that octane rating alone means nothing for power and economy without changing the engine design - in the case of our Hemi's, the spark ignition timing advance.

 

[Jeepwalker]

I took it as the engine didn't make any more power past 29* of advance. I'm assuming they were getting 'ping' after that point.

Yeah, it was an interesting video!

 

[Trucker J]

Simple fix: STP Octane Boost from Wal-Mart treats 20 gallons at $4 per bottle. Takes 87 to 90 and I save $45 per fill up. I have a 40 gallon tank.

 

[Wild one]

How the hell did I miss this episode?

Anyway, I watched, and am a tad confused. So they took the Chevy LS 6.2 and ran it with a bunch of different octane gasolines, and there was miniscule difference in torque, AND ignition timing, AND AFR ratio.

Well, wait a minute - we haven't been discussing boosting the Hemi or camming it, or increasing compression either - BUT - we have been talking about advancing ignition timing with increasing gasoline octane rating because, up to a point, this yields more torque and power from a STOCK engine.

Yet, these guys kept saying their engine "liked" the same ignition timing regardless of gasoline octane rating. Huh??? Are they saying they can't advance beyond 29 degrees BTDC because (1) they don't have a timing tool (2) that's as advanced as the engine can take on any octane?

This episode is VERY misleading for engine enthusiasts. It seems it's made for the average slob to prove that octane rating alone means nothing for power and economy without changing the engine design - in the case of our Hemi's, the spark ignition timing advance.

There's a point of dimishing returns by advancing the timing any farther then the engine wants,not the fuel.Timing is more a function of how well the head /combustion chamber and quench area function as a unit.Pretty well any head/piston combo manufactured in the last dozen years are designed to be a fast burn chamber,and require way less timing then the old school engines of yesteryear required to have a complete burn,the days of 40+ degree's timing are long gone now.So to keep advancing the timing past what is required for a complete burn,starts to hurt power,as the piston starts running into cylinder pressure way before it's made it over top dead center,and is on it's way back down and putting force on the crank.

 

[Docwagon1776]

Simple fix: STP Octane Boost from Wal-Mart treats 20 gallons at $4 per bottle. Takes 87 to 90 and I save $45 per fill up. I have a 40 gallon tank.

It will not take 87 to 90 with a bottle. It'll take it to somewhere between 87.2 to 87.5 octane.

 

[Wild one]

Simple fix: STP Octane Boost from Wal-Mart treats 20 gallons at $4 per bottle. Takes 87 to 90 and I save $45 per fill up. I have a 40 gallon tank.

Boostane might do that,but not a chance in hell STP's octane booster does what you're claiming.If you're a fan of octane boosters,you should be pulling the plugs fairly often and checking them,as the majority of octane boosters are hard on the plugs,and will leave a white flaky residue on the plugs,that isn't condusive for prolonging the life of the plugs

 

[HEMIMANN]

There's a point of dimishing returns by advancing the timing any farther then the engine wants,not the fuel.Timing is more a function of how well the head /combustion chamber and quench area function as a unit.Pretty well any head/piston combo manufactured in the last dozen years are designed to be a fast burn chamber,and require way less timing then the old school engines of yesteryear required to have a complete burn,the days of 40+ degree's timing are long gone now.So to keep advancing the timing past what is required for a complete burn,starts to hurt power,as the piston starts running into cylinder pressure way before it's made it over top dead center,and is on it's way back down and putting force on the crank.

I detect I'm being considered old. I resemble that inference!

However, if timing was unchanged in the GM LS 6.2 between 87 octane and 91 octane gas test, why is it changed for our Hemi engines with different octane gas? Perhaps the Hemi combustion area isn't fast burn design? I'd believe that, since the entire claim to fame for the Hemi is the cross-flow breathing with siamese valve orientation, with scavenging that doesn't really kick in until racing rpm (5,000+ rpm) - as shown on another Engine Masters episode I watched (it was the 426 Hemi vs. the 440 big block). It was very evident on the torque curve map.

Even more reason I wanted a DOHC 6.0L V8 instead of the Hemi. In fact, I wanted the 6.2L Chevy V8, but they wouldn't put it in a truck back when. They kept putting in the archaic 6.0L V8.

Thanks for bringing me into the 21st century, btw.

 

[ramffml]

I detect I'm being considered old. I resemble that inference!

However, if timing was unchanged in the GM LS 6.2 between 87 octane and 91 octane gas test, why is it changed for our Hemi engines with different octane gas? Perhaps the Hemi combustion area isn't fast burn design? I'd believe that, since the entire claim to fame for the Hemi is the cross-flow breathing with siamese valve orientation, with scavenging that doesn't really kick in until racing rpm (5,000+ rpm) - as shown on another Engine Masters episode I watched (it was the 426 Hemi vs. the 440 big block). It was very evident on the torque curve map.

Even more reason I wanted a DOHC 6.0L V8 instead of the Hemi. In fact, I wanted the 6.2L Chevy V8, but they wouldn't put it in a truck back when. They kept putting in the archaic 6.0L V8.

Thanks for bringing me into the 21st century, btw.

GM has a 6.6 gasser now since about 2019/2020. It used to be paired with the pathetic 6 speed which meant that Ford and Ram ate its lunch in performance and probably MPG.

But this week is "heavy duty truck" week and Chevy just announced that next year they are pairing the 6.6 with a 10 speed. Might be worth a look.

 

[Wild one]

I detect I'm being considered old. I resemble that inference!

However, if timing was unchanged in the GM LS 6.2 between 87 octane and 91 octane gas test, why is it changed for our Hemi engines with different octane gas? Perhaps the Hemi combustion area isn't fast burn design? I'd believe that, since the entire claim to fame for the Hemi is the cross-flow breathing with siamese valve orientation, with scavenging that doesn't really kick in until racing rpm (5,000+ rpm) - as shown on another Engine Masters episode I watched (it was the 426 Hemi vs. the 440 big block). It was very evident on the torque curve map.

Even more reason I wanted a DOHC 6.0L V8 instead of the Hemi. In fact, I wanted the 6.2L Chevy V8, but they wouldn't put it in a truck back when. They kept putting in the archaic 6.0L V8.

Thanks for bringing me into the 21st century, btw.

The earlier Gen 2 Hemi head doesn't really compare to the later Gen 3 head,other then both are a cross flow head.

 

[HEMIMANN]

The earlier Gen 2 Hemi head doesn't really compare to the later Gen 3 head,other then both are a cross flow head.

I meant the current Gen 3 Hemi head, though. I know I mentioned the Gen 2 head that was tested in the episode, but didn't think you can really make any Hemi cross-flow head efficient. Same problem as a 2 stroke engine, which is why they became obsolete, at least for emissions (also efficiency).

 

[HEMIMANN]

GM has a 6.6 gasser now since about 2019/2020. It used to be paired with the pathetic 6 speed which meant that Ford and Ram ate its lunch in performance and probably MPG.

But this week is "heavy duty truck" week and Chevy just announced that next year they are pairing the 6.6 with a 10 speed. Might be worth a look.

I know of the 6.6, but haven't read much about it. I've seen the 10 speed Ford (it's NOT an Allison - only falsely branded to deceive buyers) lampooned - many problems with it.

 

[Wild one]

I know of the 6.6, but haven't read much about it. I've seen the 10 speed Ford (it's NOT an Allison - only falsely branded to deceive buyers) lampooned - many problems with it.

The new GM's with the big motor and 10 speed kick a 5.7/8sp's ass to the curb. A young neighbour has one,and the damn thing is impressive as all hell,plus pulls down better milege then the hemi will,but the truck has already been in for new pushrods at about the 15,000 mile mark