Mix the mid grade yourself and save?

[Deercamp]

Used to almost exclusively buy regular gas at a nearby Gulf station for my 2004 GMC Sierra v8 which called for regular grade fuel. In less than 60,000 miles i replaced 3 oxygen sensors. (The v8 actually had 4 oxygen sensors.) While Gulf is a name brand fuel in my area, it is not a top tier fuel. Thus it may lack detergent additives. I subsequently learned that fuel quality and lack of cleaning agents impacts various engine components, including O2 sensors.

In light of some of the above blog comments, suggest you check out below comments from a BMW service shop article :

“How can your choice of gas affect your RESULT IN A FAILED EMISSIONS TEST”

“Another part of your car that can be affected by your choice of gasoline is the oxygen sensor. This small but vital component monitors how much oxygen is in your car’s exhaust, helping to increase performance and decrease harmful emissions. Using low-quality fuel that lacks a cleaning agent, or using a lower octane gas than is recommended for your car, can cause your oxygen sensor to fail. And if that happens, you could fail your emissions test.”

My GMC ran well, no indication of engine issues until the check engine light went on, each time one of the 4 O2sensors failed.
Thus I have only used top tier fuels for the past decade, and no oxygen sensor failures.

 

[Jerrybob]

I don't waste money on mid grade fuel. I use 87 octain in my 2020 Ram 1500 5.7 with no issue. I tested runing 89 compared to 87 with very little or no difference in fuel economy or power. I expected to feel a difference with the higher octain but it wasn't enough to distinguish between them other than price. I have almost 70- k on it now with zero issues of any kind, I have the oil changed every 4 thousand miles at my dealership keep the air filter clean and changed out as required rotate tires at every oil change and keep psi at 36 and have no complaints. I'm sure some will say you don't need to chang oil as often as I do but I purchase three oil changes at a time from Ram which makes my oil change and service cost 58.00 per change including full synthetic, mopar oil filter topping off all fluids and tire rotation. Can't beat that!

How does the 3 oil change thing work......do you have a coupon? I can't find anything on the MOPAR site??? Thanks

 

[mdc1990zr1]

How does the 3 oil change thing work......do you have a coupon? I can't find anything on the MOPAR site??? Thanks

I bought my daughter a 2022 Jeep Wrangler and I believe it came with some complimentary oil changes and tire rotations

 

[GTyankee]

When i bought my 2016 Ram ecodiesel
Some kind of arrangement was made, i got 10 complimentary Oil Changes, that was done in the Finance Officers enclosure.

It may have been because i handed him a Cashiers Check for the full price of the vehicle ??

That was a crazy day, my 2016 Ram was unloaded off the Car Hauler, where it was Inspected & driven back the Detail Shop.
At about 9 AM i drove to the dealership to see if the truck had come in, i was walked back to the Detail Shop & then i was walked to the Finance Office, signed all the paperwork, paid for the truck & drove it off the lot

 

[sailfishcc13]

Not every octane booster works, only use certain ones. Lucas is one that actually works, there is a test on the net out there somewhere. Most of them actually do not work if you believe the test.

I think I posted it here before, check search dunno.

my manual for my 2021 hemi 5.7 advises not to add an "octane booster" . what else an be added for performance and help with mpg's?

 

[Scottly]

Anybody know what that engineered fuel sold at Home Depot is? They have it in 40:1, 50:1, and no mix....doesn't smell like gasoline.

 

[tjfdesmo]

2 stroke motors are entirely different, require mid to high octane gas without any alcohol (exception - direct fuel injected). My dumb buddy just bricked his Stihl 026 saw with ethanol gas. Dissolving his plastic carb and scoring his cylinder. Now he finally listens to me. My 026 saw is 34 years old and runs like a top. Inspected cylinder recently - you can still see the piston skirt machining marks with no wear or deposits. Hundreds and hundreds of hours on it. I'll post pic again if you want to see.


Alcohol gas doesn't store well, even with stabilizer. Small engines don't like it with plastic parts in them - plastic carburetors and gaskets, etc. They get dissolved. Further, alcohol leans out small engine mixtures and causes engines to run too hot. Finally, small engines have low compression ratios that don't want higher octane or alcohol. They cause excessive unburned fuel deposits on heads, valves, and rings. Esp. flathead engines.

It's a shame EPA and corporations have made something relatively simple a complete mess for consumers.

When I was a Stihl dealer they allowed up to 10% alcohol. I still have the test kit in my toolbox. Yup, Premium in small engines causes more carbon buildup. This was readily apparent on Onan twins needing de-carb, as you well know. Small equipment tend to sit around a lot. The alcohol in the fuel being hygroscopic continues to draw moisture and will eventually cause "phase separation" and settle out. That's when the real corrosion, and problems begin. Locked up fuel pumps, etc.

 

[HEMIMANN]

When I was a Stihl dealer they allowed up to 10% alcohol. I still have the test kit in my toolbox. Yup, Premium in small engines causes more carbon buildup. This was readily apparent on Onan twins needing de-carb, as you well know. Small equipment tend to sit around a lot. The alcohol in the fuel being hygroscopic continues to draw moisture and will eventually cause "phase separation" and settle out. That's when the real corrosion, and problems begin. Locked up fuel pumps, etc.

Well, Onan twins were flatheads with low compression ratios, ancient architecture never meant for alcohol or high octane. Back when gas was just gas before corporations started buying legislators in earnest.

Just returned from Wisconsin where it still is legal to use non oxy gas in cars and trucks.
Unlike here in Minnesota where the Ag Lobby bribed state legislators to make it illegal, then launch a massive disinformation campaign to convince an ignorant electorate their extortion is good for them. Fuching banana republic.

 

[noupf]

I've been doing this for years. Typically with close to a full fill up, I put in about 9 gallons of 93 and another 18 gallons of 87.

9 gallons of 93 octane at $4.19
18 gallons of 87 octane at $3.45
Avg Octane 88.99 - avg price per gallon mixed is $3.39

89 Octane at the pump is about $3.99 in my area today.

I'll gladly save ~30 cents per gallon ( Saves me $8.81 for a 27 gallon fill up ) to have 89.

 

[HEMIMANN]

I still don't like blended fuels because I don't know how they're burning.

87 octane gas needs delayed ignition, or else detonation. The way Hemi detects 87 octane gas is by letting the engine detonate on and off as it cycles through ignition timing algorithms. A member with a full scanner showed this to us some time ago.

Default ignition timing is advanced for 89 octane gas. But there is no such thing as 89 octane gas molecules. There is only 87 and 91 or whatever (92, 93). A blend does not become 89 octane. It is 87 and 91. Advance ignition timing will detonate the 87 octane gas molecules. Delayed ignition timing will partially burn 91 gas molecules, leaving deposits. Neither is good.

My solution is 91 octane all the time with top tier detergent additive to reduce the unburned gas from 89 octane ignition timing. 89 is a stupid marketing gimmick that reduces engine longevity.
For those that buy new every couple years, ignore all of this.

 

[MontanaHandyman]

For those that buy new every couple years, ignore all of this.

I like to keep my vehicles til the wheels fall off, so this is good stuff to know!

 

[Atcer2018]

Generally, mid octane is a waste of money for small 4 stroke motors, and can cause more engine deposits - if they are low compression ratio - like Briggs and Strattons (6:1 CR). There is no need for higher octane until getting into higher CR's, typically more than 9:1.

2 stroke motors are entirely different, require mid to high octane gas without any alcohol (exception - direct fuel injected). My dumb buddy just bricked his Stihl 026 saw with ethanol gas. Dissolving his plastic carb and scoring his cylinder. Now he finally listens to me. My 026 saw is 34 years old and runs like a top. Inspected cylinder recently - you can still see the piston skirt machining marks with no wear or deposits. Hundreds and hundreds of hours on it. I'll post pic again if you want to see.

Mobil is Top Tier Gas, but usually doesn't offer nonoxy.
For small engines, I get non oxy (alcohol) 87 octane gas at Cenex. Cenex is Top Tier detergents, also. Oddly enough, Cenex is a major promotor of alcohol gas and political lobbying for tax money. Go figure.

Alcohol gas doesn't store well, even with stabilizer. Small engines don't like it with plastic parts in them - plastic carburetors and gaskets, etc. They get dissolved. Further, alcohol leans out small engine mixtures and causes engines to run too hot. Finally, small engines have low compression ratios that don't want higher octane or alcohol. They cause excessive unburned fuel deposits on heads, valves, and rings. Esp. flathead engines.

It's a shame EPA and corporations have made something relatively simple a complete mess for consumers.

Thank you for this. I learned something as I’ve been doing it bassackwards for a while now. Been using 87 10% ethanol gas mixed with synthetic 2 cycle for my two stroke saw, blower and trimmer and 91 octane ethanol free marina gas for my 4 stroke Kawasaki V-twin with an 8:1 CR. I should be doing it the other way around with the octanes. My question is do the 2 strokes need 89 octane? I live in a metro area of VA and we have zero non-ethanol fuel at gas stations. I can only get 91 octane ethanol free gas at a local marina. Can I run the 2 strokes on 91?

 

[HEMIMANN]

I can't tell you guys how much longer your engine will statistically last without long term durability studies Ram may or may not have conducted. Big manufacturers usually do, but won't share results.

You may get 1 hour more run time, or 1,000 hours more run time, but your engine will have fewer deposits and wear. That we know from low hour engine testing with various octanes and ignition timing.

 

[HEMIMANN]

Oh - and the other benefit is the engine loses power more slowly as well. All engines lose power over time (after initial break-in) due to wear and deposits. Minimizing the rate of power loss over time is important for those of us that own long term.

 

[Docwagon1776]

Default ignition timing is advanced for 89 octane gas. But there is no such thing as 89 octane gas molecules. There is only 87 and 91 or whatever (92, 93). A blend does not become 89 octane. It is 87 and 91. Advance ignition timing will detonate the 87 octane gas molecules. Delayed ignition timing will partially burn 91 gas molecules, leaving deposits. Neither is good.

Literally everything about this is wrong, starting with the notion any octane gasoline is homogenous at the molecular level.

I've never worked in a refinery, but I was trained in improvised explosives and booby traps, to include things like dust charges that rely on calculating a lower and upper explosive limit.

Before anyone acts on the above advice, I'd recommend spending a few minutes researching refining processes, blendstocks and additives, and the chemical makeup of gasoline.

 

[HEMIMANN]

Literally everything about this is wrong, starting with the notion any octane gasoline is homogenous at the molecular level.

I've never worked in a refinery, but I was trained in improvised explosives and booby traps, to include things like dust charges that rely on calculating a lower and upper explosive limit.

Before anyone acts on the above advice, I'd recommend spending a few minutes researching refining processes, blendstocks and additives, and the chemical makeup of gasoline.

I have. I worked for Mobil Oil, trained in refining and applications.
Octane rating does cover a range of hydrocarbons, I simplified for the audience.

It would help for a review of the scanner documentation provide some months back to understand this topic. Actual Hemi detonation data with the ECM knock sensor responses before coming on here with a general statement of dusmissal.

I would encourage rephrasing your post.

 

[Docwagon1776]

I have. I worked for Mobil Oil, trained in refining and applications.
Octane rating does cover a range of hydrocarbons, I simplified for the audience.

It would help for a review of the scanner documentation provide some months back to understand this topic. Actual Hemi detonation data with the ECM knock sensor responses before coming on here with a general statement of dusmissal.

I would encourage rephrasing your post.

I remember the post, and I understand how knock detection works. I also understand enough chemistry to know the difference between a molecule and a compound and, as stated, demolitions to know how autoignition and explosion upper and lower limits function. I'll concede there's plenty I don't know, like how detergent additives function in such an environment.

Perhaps you oversimplified it that point hoping the layman would get it, but are you really telling us that there is an "87 gas molecule" that makes up 87 octane gas? That gasoline isn't actually, regardless of octane, a blend of multiple compounds, each with their own ignition temperature and rates? And you're telling us that an aerosolized cloud of flammable material will preferentially burn those "87 molecules" out of the compounds while leaving the "91 molecules" unburnt? If so, why, exactly, is there an 87 molecule and a 91 molecule, but not an 89 molecule? Bruh.

But let's pretend gasoline is just made up of 87 molecules and 91 molecules. The only thing timing addresses is *when the spark fires*, and the spark is hot enough to touch off both 87 octane "molecules" and 91 octane "molecules". Even if it wasn't, the energy release from the 87 "molecules" would touch off the 91 "molecules" next to them, there isn't *that* much difference in stability between the two grades. So why would the 91 "molecules" not burn? Again, bruh. Do you imagine there's two flame fronts zig-zagging molecule to molecule or that, somehow, the 91 just survives the burn of the 87 because...why?

No need for me to rephrase anything, what I quoted from you is nonsense.

 

[slickracer]

I run Sheetz 88 octane E15, does well. If I was towing I would bump up the octane.