Shell and Kroger 87 octane causing detonation

[GJM120]

To add: Top Tier gas stations don't variate the amount of detergent prescription between their regular and premium grades. Tried telling a friend this and he just absolutely refused to believe it.

Buried in this thread is info to the contrary.

Fuel Tanker Driver Here

I drive a fuel/gasoline tanker for a living. Been a visitor of this site for years and thought I'd go ahead and create a profile today. Just by browsing through the forums, seems to be a bit of misunderstanding about gasolines and where/how they end up as the final retail product. I'm open for...

bobistheoilguy.com

 

[Skippy722]

To add: Top Tier gas stations don't variate the amount of detergent prescription between their regular and premium grades. Tried telling a friend this and he just absolutely refused to believe it.

Top Tier specifies a minimum level above EPA requirements but doesn’t set a ceiling. Some brands may use the same amount across all grades but it isn’t required by Top Tier.

 

[CleanSump]

BLUF:
If your car doesn't run well on Shell/Kroger 87 octane gas, don't buy it.

 

[SubZero350]

BLUF:
If your car doesn't run well on Shell/Kroger 87 octane gas, don't buy it.

It's a little more than "it just doesn't run well on Shell/Kroger gas". My vehicles actually ping/detonate on Shell/Kroger 87 octane gas but don't on other brands. Am I to believe all the other brands' 87 octane fuels are actually testing higher than 87 octane? Or would I be more likely to believe Shell/Kroger 87 octane fuel isn't actually performing to 87 octane standards?

 

[kschachn]

It's a little more than "it just doesn't run well on Shell/Kroger gas". My vehicles actually ping/detonate on Shell/Kroger 87 octane gas but don't on other brands. Am I to believe all the other brands' 87 octane fuels are actually testing higher than 87 octane? Or would I be more likely to believe Shell/Kroger 87 octane fuel isn't actually performing to 87 octane standards?

That is highly unlikely especially in terms of a corporate problem. If you actually suspect this then it should be reported to your state, this is typically taken very seriously.

Terminals have numerous safeguards for octane rating and it is tightly controlled. A conspiracy to sell gasoline below a listed octane rating would be quite a problem. Check out the thread linked above from GoldDot40, I think there were others as well.

 

[SubZero350]

That is highly unlikely especially in terms of a corporate problem. If you actually suspect this then it should be reported to your state, this is typically taken very seriously.

Terminals have numerous safeguards for octane rating and it is tightly controlled. A conspiracy to sell gasoline below a listed octane rating would be quite a problem. Check out the thread linked above from GoldDot40, I think there were others as well.

The scan data and my ear don't lie. I have multiple vehicles that suffer from significantly more detonation (registered as knock/knock retard in the scan data) while running Shell or Kroger 87 octane than they do while running on 87 octane from Marathon, Sunoco, Sam's Club, Murphy USA, BP and Speedway. Something is different between the Shell/Kroger 87 octane fuel and everyone else's 87 octane fuel.

Who do I contact at the state level? Department of weights and measures?

 

[Greasymechtech]

Do an at home ethanol test with your various gas stations. Sounds to me that some might be cheating and overdosing the ethanol.
More ethanol... more octane... less BTU's---- less chance of detonation

Sounds to me that you're getting good fuel at Shell, and lesser everywhere else.

 

[fitrucker]

You should not hear knock if you use lower octane unless something else is going on, just a louder motor which is not knock. Premium your exhaust will sound louder and not because it's burning in the exhaust just because it burned completely and more exit's.

 

[kschachn]

Do an at home ethanol test with your various gas stations. Sounds to me that some might be cheating and overdosing the ethanol.
More ethanol... more octane... less BTU's---- less chance of detonation

Sounds to me that you're getting good fuel at Shell, and lesser everywhere else.

Well first off it isn't really detonation since that would damage the engine. It pre-ignition pinging.

And the BTU content has nothing to do with that. You're mixing two things in your post, more ethanol would increase the octane rating and that would reduce the pinging.

 

[Jetronic]

he means, there's more fuel (with increasing ethanol content) so more evaporative cooling, like running a richer mixture

 

[kschachn]

he means, there's more fuel (with increasing ethanol content) so more evaporative cooling, like running a richer mixture

Does that cause pinging?

 

[snarl]

It might be a RON/MON difference.

What Does RON and MON Mean?

Octane levels play an important part in determining the performance, efficiency and suitability of fuel. Testing for the research octane number (RON) and motor octane number (MON) is a useful way...

www.petro-online.com

 

[Jetronic]

Does that cause pinging?

not having enough cooling can, but I don't know if this is the case here of course

 

[SC Maintenance]

Very interesting. What vehicle(s) is this happening in? I thought pre-ignition was a thing of the past with knock sensors and ECU controlled Engines. I know a couple guys with LR4's that spec 89 octane. They just run 87. There mpg drops - and likely performance but they don't care. They would know what pinging was.

I would also guess it has to do with the amount of ethanol, more or less ethanol causing it is above my pay grade. Ethanol does have more octane, but it also has less energy and engines tend to ping under load?

 

[fitrucker]

Ethanol cools combustion. Lowering octane requirements. I notice different brands don't work well in my cars but too many variables to figure why. Like bad gas, season changes and state of tune in the ecu. When filling up your car should go do default and do timing sweeps to retune for octane. Maybe that is the problem until a few miles are put on. Also if there is knock it would show up as mis fire and the engine would not fire in that cylinder for a few cycles but highly unlikely.

 

[kschachn]

Ethanol cools combustion. Lowering octane requirements. I notice different brands don't work well in my cars but too many variables to figure why. Like bad gas, season changes and state of tune in the ecu. When filling up your car should go do default and do timing sweeps to retune for octane. Maybe that is the problem until a few miles are put on. Also if there is knock it would show up as mis fire and the engine would not fire in that cylinder for a few cycles but highly unlikely.

Flame temperature isn’t relevant either. By the time the fuel mixture is ignited it’s too late. In terms of the fuel, the only thing that matters is the octane rating which is the resistance to ignition from sources other than the spark plug.

The mechanical condition of the engine does make a difference. The presence of carbon deposits in the combustion chamber will make a big difference. But in terms of the fuel, the resistance to preignition is entirely dependent on the octane rating.

An overheated engine will ping because there are more potential sources of ignition besides the spark plug. But that is outside the normal operating conditions for the engine.

 

[Greasymechtech]

BTU has everything to do it with. Quit making a fool out of yourself KC. Too much heat! You lose some much with ethanol, and maybe not enough for some dirty engines. Using octane as a bandaid for not being able to control the heat that the fuel produces is pathetic. That heat is causing excessive pressure. When was the last time anyone heard detonation on their 'cold' engine before coolant/oil temps rise? Why do some use a lower temp thermostat, bigger intercooler, water injection, bigger radiator/fans.... whatever? TO UNLOAD THE BTUs. Some members here need to get some real world experience.

I really think that many just have pathetically running vehicles, marginal unmaintained cooling systems, excessive carbon buildup on pistons, dirty injectors with horrible spray patterns, partially clogged or less effective EGR, vacuum leaks, lean A/F ratios, bad o2 sensors, and questionable knock sensors..... and some fuels just bring it out more than others. But, its easier to trash a fuel brand. I'd want to figure out what is wrong with the engine before trashing the fuel station. That fuel is giving you a warning on bigger problems, or simply ignored problems. Some get that warning with oils, ATFs, PSFs, and various filters too. If it doesn't sound/feel right, ask yourself why, or cover up the problem. A different brand or fuel or higher octane is a form of covering up for an issue.

Well, all grades of Shell run perfectly fine in my engines. I am well travelled and lived in many states, and haven't experienced this Shell syndrome anywhere. Either complain to Shell, Kroger, your local news, or your state's regulators. Nothing we say here is going to help you. You already can't use common sense enough to just avoid those stations or run 89.

I see 3 GM products listed by the OP and all are pushing that ~20 year vintage. Sure, they all are in perfect state of tune and spotless internally. Maybe you should complain to GM too.

 

[kschachn]

What on earth? What I said was correct. The BTU content of the fuel is not related to the resistance towards preignition. Yes, an engine running too hot will be more prone to pinging. And if that mixture is detonating then you’re done here.

 

[fitrucker]

Flame temperature isn’t relevant either. By the time the fuel mixture is ignited it’s too late. In terms of the fuel, the only thing that matters is the octane rating which is the resistance to ignition from sources other than the spark plug.

The mechanical condition of the engine does make a difference. The presence of carbon deposits in the combustion chamber will make a big difference. But in terms of the fuel, the resistance to preignition is entirely dependent on the octane rating.

An overheated engine will ping because there are more potential sources of ignition besides the spark plug. But that is outside the normal operating conditions for the engine.

Ethanol cools the surfaces as it evaporates. Yes ethanol can cause carbon deposits but it's because of the added fuel the ecu uses to prevent knock. The spark plug won't fire if it detected pre-ignition which is worse than detonation. You are proving my point to use the best quality gas which means higher octane.

If you have an overheated engine you have bigger problems than what fuel you use. Most engines are aluminum which dissipates heat quickly. Also DI engines run cooler at idle so should not have heat issues.

Also retarded timing keeps heat in the cylinder head compared to the exhaust. The problem with premium gas is old stale gas but if fresh premium is found it's worth every penny.

E10 has been in our fuel for 50 plus years and have not seen the problems many are complaining about. It basically raises octane and reduces carbon dioxide.

 

[kschachn]

E10 has been in our fuel for 50 plus years and have not seen the problems many are complaining about. It basically raises octane and reduces carbon dioxide.

Yeah Southeastern Wisconsin has been an EPA nonattainment zone since the 90s and all we can buy is RFG. I have never seen a problem with it.