Help! wrong fuel put in the car!

2271 Views 34 Replies 16 Participants Last post by mpfla1, 2 mo ago

cincySS8807

Discussion Starter · 2 mo ago

Hey all. i let my brother take my car as long as he filled it up since it was low (maybe 1/8th of a tank left since im a bad owner and was lazy) when he came back he told me he filled it up with gas. long story short im almost certain he filled it with 87 instead of 93 like i told him to. what should i look for or do? i was thinking maybe add an octane booster? the car is cammed with upgraded valve springs long tube headers x pipe

21 - 35 of 35 Posts

Kevin0311

· #21 · 2 mo ago

dyno results with octane booster

2014ltdltz

· #22 · 2 mo ago

Another option is to do what is called a serial dilution:

run the tank down part way
then top-off with the highest octane you can get (the higher the better)
you can repeat the process as frequently as you like as it will incrementally bump the the tank's average octane up incrementally

Oh, and tell your brother his driving privileges have been revoked.

Reactions: 5

willy92

· #23 · 2 mo ago

TheMealOnWheels said:
This may be an old wives tale as well, but I never run below a 1/4 tank due to the potential for the fuel to be warmer, which reduces the cooling effect on the pump.

The pump is in a fuel bucket that is always full, which acts as a medium for transferring heat from the pump. Fuel returned from pressure regulation is usually returned to the bucket. If you have less volume of fuel to circulate, there's less heat capacity to absorb that heat. Hotter fluid means the pump is in a hotter bath of fuel, which means less heat dissipation from the pump, causing more strain on the pump.

Makes sense to me, but I certainly heard that through the grapevine and not directly from a fuel system designer at gm. But until one of you can tell me I'm wrong, THAT'S why I'll never let it get below 1/4 tank.

No dispute there, sounds like sound reasoning for a high output car...in fact, that may be part of what bit me in the butt on my RX7. That car actually has a resister in the fuel pump circuit that it bypasses under boost, thus doubling (or at least
increasing) the fuel pressure and volume while under boost, which would certainly increase fuel pump heat and the necessity to have enough fuel to keep the pump cool and operating.

Kuel!

Reactions: 1

MillaMilla94

· #24 · 2 mo ago

2014ltdltz said:
Another option is to do what is called a serial dilution:

run the tank down part way

then top-off with the highest octane you can get (the higher the better)

you can repeat the process as frequently as you like as it will incrementally bump the the tank's average octane up incrementally

Oh, and tell your brother his driving privileges have been revoked.

Fwiw, my brother absolutely does NOT have SS driving privileges to begin with! Lmao! He has a Mach 1 Mustang that has seen a curb, and a deer, and that's just the things we know of. There is absolutely no way on God's green Earth that I'm going to let him behind the wheel of my ESSther! 😂

Reactions: 1

wilkin4

· #25 · 2 mo ago

In stock form, there is a low octaine timing table that gets triggered when a certain amount of knock is detected. What that trigger point is, not sure.
Bottom line, you should be ok, if you don't go crazy and drift regularly....

Reactions: 1

2014ltdltz

· #26 · 2 mo ago

Taking it to the extreme, be happy your sibling did not fill it with diesel (...or DID he????

).

Before anyone chimes-in saying that would be impossible due to diesel pumps having a larger diameter fill nozzle than would fit in a gas filler neck, I have firsthand knowledge of a friend whose now ex-wife did it, so it CAN happen.

Reactions: 3

Kevin0311

· #27 · 2 mo ago

op says car is cammed so betting has been tuned and probably not for 87 anymore

Reactions: 2

wilkin4

· #28 · 2 mo ago

Kevin0311 said:
op says car is cammed so betting has been tuned and probably not for 87 anymore

The low octane timing table will protect it, unless disabled....

Reactions: 1

cincySS8807

Discussion Starter · #29 · 2 mo ago

2014ltdltz said:
Another option is to do what is called a serial dilution:

run the tank down part way

then top-off with the highest octane you can get (the higher the better)

you can repeat the process as frequently as you like as it will incrementally bump the the tank's average octane up incrementally

Oh, and tell your brother his driving privileges have been revoked.

thats basically what my tuner said to do! and yes his rigfhts have been revoked unless i get to be his best man haha

MillaMilla94 said:
Fwiw, my brother absolutely does NOT have SS driving privileges to begin with! Lmao! He has a Mach 1 Mustang that has seen a curb, and a deer, and that's just the things we know of. There is absolutely no way on God's green Earth that I'm going to let him behind the wheel of my ESSther! 😂

i got lucky and he drives slower and is more careful. but fully ban hammered him

2014ltdltz said:
Taking it to the extreme, be happy your sibling did not fill it with diesel (...or DID he???? ).

Before anyone chimes-in saying that would be impossible due to diesel pumps having a larger diameter fill nozzle than would fit in a gas filler neck, I have firsthand knowledge of a friend whose now ex-wife did it, so it CAN happen.

if it were diesel youd be seeing me in cuffs not on the forum lol

Reactions: 4

GXPaycheck

· #30 · 2 mo ago

GXPaycheck said:
According to the owners manual, you can use either. I’ve run regular on a regular basis (no pun intended) when prices were crazy.

I‘m amending this to add that if you have an aftermarket tune set for premium fuel, drive nice for a while to burn out the regular then fill it up with the good stuff.

Reactions: 1

gregscher

· #31 · 2 mo ago

cincySS8807 said:
Hey all. i let my brother take my car as long as he filled it up since it was low (maybe 1/8th of a tank left since im a bad owner and was lazy) when he came back he told me he filled it up with gas. long story short im almost certain he filled it with 87 instead of 93 like i told him to. what should i look for or do? i was thinking maybe add an octane booster? the car is cammed with upgraded valve springs long tube headers x pipe

I have ALWAYS run regular gas in my 2014 SS. It runs like a top. I tried two different tanks of Premium, and the only difference that I noticed was the price of the gas! Like you, I have mine dialed up, too. Just stop wasting your money on Premium gas when there is no benefit to it.

Reactions: 2

G8a550

· #32 · 2 mo ago

cincySS8807 said:
thats pretty much my plan to just go for a cruise as much as i can and drain it quickly. ill shoot the tuner an email and see what he says.

Before you do make sure you tie one of your brother's legs to the back of the car.

Tee

· #33 · 2 mo ago

I've had my 2016 MT now for just over 7 years and 41k miles and tried these different kinds of gasoline... regular E10 87, no ethanol 90 and 93 and E10 93. The E10 87 and both no ethanol fuels each over intervals of about 2500 to 5000 miles yielded a measurable one-half to one mile/gallon more than E10 93.

Though I saved a bit of money using the E10 87, the engine would frightfully ping upon a hot restart after the engine had been off for less than about 3 minutes. For that reason, I stopped using it over four years ago and now use any Top Tier brand 93 octane gasoline. Otherwise, the E10 87 behaved well if the engine was allowed to cool a bit before restarting it.

Reactions: 1

cincySS8807

Discussion Starter · #34 · 2 mo ago

G8a550 said:
Before you do make sure you tie one of your brother's legs to the back of the car.

pretty sure thatd be considered a hate crime...

mpfla1

· #35 · 2 mo ago

The Fords seem bad for this. I heard pinging in my 2000 Mazda 3000 V6 and 2010 V8 Ford Explorer. Owner's manual says regular but if you hear pinging move up gas. One tank is not going to hurt the car, just drive where there is no pinging when you step on it. That is what it is bad for the car.

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