Shell and Kroger 87 octane causing detonation

[SubZero350]

I think Kroger gets supplied with Shell gasoline. If I fill up any of my vehicles with Shell or Kroger 87 octane fuel, my vehicles don't perform well. I can watch the KR (knock retard) occur on my scan tool when running this fuel (pulls about 1-2 deg out at moderate loads and up to 5 deg at heavy loads). I don't have this same issue if I fill up with 87 Octane from Sunoco, Sam's Club, Murphy USA, BP, Marathon, Speedway or Casey's.

Is anyone else experiencing issues when running Shell or Kroger 87 octane fuel?

 

[slacktide_bitog]

Welcome to BITOG

What kind of car do you have? What octane is required? Do you have a turbo?

 

[SubZero350]

I have a turbo car but it gets 93 octane premium. I never put less in it.

The vehicles that have trouble with Shell/Kroger 87 octane are listed below:

2002 Buick LeSabre 3.8L N/A (L36) - 87 octane is all that is required
2004 Chevy TrailBlazer 4.2L N/A - 87 octane is all that is required
2004 GMC Sierra 4.8L N/A - 87 octane is all that is required

 

[PontiacHO]

My opinion only…
Branded fuel is always better blended upper tier fuel.
Not sure why Shell is an issue unless the carrier is hauling from a storage facility with a stock of winter blend.

 

[mrsilv04]

100% of the fuel in this area comes from the same tank farm on the edge of town. The only difference in the fuel from station to station, would be the additives that are put in for the specific station who is selling the fuel (If there are any additives). The fuel sold by 'TopTier' stations should be different because of the additives.

The only way that I can get different fuel is to drive 40 miles away in just about any direction, and get fuel that originates from a different supplier.

 

[kschachn]

If you really do suspect the octane rating is deficient then you should report the station(s) to your state. Here in Wisconsin that would be the Department of Agriculture, Trade and Consumer Protection.

 

[BMWTurboDzl]

The sticker on the pump indicates the minimum not the maximum. Worst case is that the station isn't actually getting 87.

 

[I<3oil]

I know there's a pretty famous tuner for GM trucks that is not a big fan of Shell gasoline. He's explained it in depth before but I forget the exact reason(s), something to do with additives.

 

[SubZero350]

Based on my own limited testing (just trying different brands of 87 octane from various stations), I can conclude that either what Shell and Kroger is selling is lower than 87 octane OR the 87 octane rated fuels sold at all the other stations I've tried is actually higher than 87 octane.

 

[GON]

I can't answer your observations about Shell fuel and dentonation. But I want to share that different fuel mixes of 87 octane appear to cause sometimes dentonation and/ or significant changes in fuel mileage on my 6.8l ford v10 gasser. I have guessed the dynamics of dentonation and fuel mileage was due to different mixes of ethanol in the fuel.

Is it possible the Shell fuel is using a different mix of ethanol than you are purchasing at non shell supplied retailers?

 

[Malo83]

I use Shell exclusively, all three grades and haven't noticed any degraded performance.

 

[FZ1]

I think Kroger gets supplied with Shell gasoline. If I fill up any of my vehicles with Shell or Kroger 87 octane fuel, my vehicles don't perform well. I can watch the KR (knock retard) occur on my scan tool when running this fuel (pulls about 1-2 deg out at moderate loads and up to 5 deg at heavy loads). I don't have this same issue if I fill up with 87 Octane from Sunoco, Sam's Club, Murphy USA, BP, Marathon, Speedway or Casey's.

Is anyone else experiencing issues when running Shell or Kroger 87 octane fuel?

Well, you now know where to buy gas.

 

[Lubener]

I think Kroger gets supplied with Shell gasoline. If I fill up any of my vehicles with Shell or Kroger 87 octane fuel, my vehicles don't perform well. I can watch the KR (knock retard) occur on my scan tool when running this fuel (pulls about 1-2 deg out at moderate loads and up to 5 deg at heavy loads). I don't have this same issue if I fill up with 87 Octane from Sunoco, Sam's Club, Murphy USA, BP, Marathon, Speedway or Casey's.

Is anyone else experiencing issues when running Shell or Kroger 87 octane fuel?

Try another brand elsewhere.

 

[chemman]

SubZero350, I stay away from Shell gas unless I have no other choice. My 1992 Olds 88 runs horribly on it and I have tried Shell from different stations in different states with the same result, so it's not just gas from one station in one locale. The 1999 Silverado we had got worse highway gas mileage using Shell 87 Octane than any other gas I have run by at least 2 MPG and it was not because it was E10 - it was E0, and in fact the E10 I filled up with after getting 23 gallons of Shell E0, got better gas mileage than I got with the Shell.

Unlike you, my 2004 TrailBlazer seems to run OK on Shell 87 Octane E10, but because of the experiences with the other 2 vehicles, I won't knowingly fill up with Shell unless, as I said earlier, I have no other option.

None of my vehicles has a problem running BP, Exxon, Costco, or gas from the local convenience stores - Royal Farms & WaWa.

 

[MRC01]

Remember that (R+M)/2 is the average of RON and MON. MON tests the fuel under heavier load, so MON is usually lower than RON. The difference is called "sensitivity". Ethanol has higher sensitivity than other octane boosters like Toluene or Xylene. So all 87 octane gasolines are not created equal. Some will ping or knock under heavy load due to low MON, even when the average (R+M)/2 is the same.

 

[benjy]

just dont use what knocks!! BUT as vehicles age carbon builds up which can cause need for required octane!! ever notice that manufactures sometimes note regular ACCEPTABLE but PREMIUM recommended so they know the ECU will adjust while lowering performance!!

 

[JMJNet]

Fuels supply are regional. What is experience in one area may not happen in other areas.
So, OP may need to state where he is from and hopefully, people from that area can chime in, if any.

I know you may not want to do that due to privacy but then the question will be a wandering generality.

 

[Greasymechtech]

Try an IVD/port/cc cleaning and a bottle or two of PEA/PIBA based FI cleaners at your next fuel fill ups. I'd also clean the TB and the AFM/MAF if equipped. Might also need to verify that temp sensors are reading properly.

Also, with that many vehicles, if you are not running all their fuel tanks empty every month, then you need to use a fuel stabilizer. I have daily drivers, summer only driver, and hardware store drivers. Gasoline could be topped off weekly in 2 off the vehicles, monthly or even quarterly in others. The latter get dosed with StabilMarine360, Lucas Safeguard, or StarTron at every fuel fill up.... just like my lawnmower, tractor, and generator fuel containers.

Being that these are older vehicles, have the spark plugs, air filters... been changed? How old is the coolant, thermostat, and radiator cap?

Otherwise, if you are having problems with regular from 2 stations, have you tried their midgrade? If the issue doesn't go away with their midgrade, then the smart thing to do is simply avoid those stations.

Shell around here tends to be pricey. As such, it volume of business is less than other stations. Volume means gasoline age is greater. Octane degrades with time at the station and in your tank.

Btw... nothing REQUIRES 87 octane. Fuel octane is a recommendation. And, most manuals state "87 or HIGHER". In this situation, you might need higher with those stations.

 

[MNgopher]

As stated, you will need to be specific as to location. Fuel supplies differ greatly in different locations - in some its whatever came from the same terminal, in others, product may have come from a specific terminal. Historically, it was possible in this area to get fuel from three distinct suppliers - and all were formulated differently though all technically 87 octane E10... Independent studies showed the difference (though in the end it was to promote one particular refiner/retailer product, but was done by the American Lung Association in the guise of promoting cleaner fuels.). The chemical composition was vastly different depending on the source, but all was technically a fungible product...

 

[Hall]

Fuels supply are regional.

I'd go as far as saying they're almost "local". I'm in SW Ohio and there are (2) fuel supply "depots" here, one in the Dayton area and one in Cincinnati/Northern KY. There's another one just 60-70 miles north in Lima OH.