87 octane vs 91 octane

[Justin]

EFI University tested their LT1 engine on their engine dyno on both 87 and 91 octane to compare the differences. 87 octane resulted in a greater than 50hp loss over 91 octane.

The LT1 is identical to your engine with the exception of the intake manifold, which has no bearing on the type of fuel needed.

 

[cekkk]

• High desert. We have two locations and both qualify as high desert, I believe. As others have said, you've got a high priced vehicle. Not wise to go cheap on its fuel. I not only run 91, but only Top Tier. Not hard to find, just look for it.

I hope you don't plan on scrimping on oil, too!

 

[dbbd1]

If the gas your using is not correct, your engine will let you know by spark knock or poor performance. If you notice on the pump, their method of determining OCTANE rating is of + or - 2 which is to be considered. Sometimes I wonder just exactly what your paying for, it is what it is. My 5.7 runs fine with the 87 octane with no lag in performance or spark knock. JMHO.
David g............

That said, where you get your gas is important too...

 

[Scottydoggs]

That said, where you get your gas is important too...

i learned this with my supercharged regal, one place i got loads of kr, fill up at another kr went away. so now i only get gas at the local BP. clearly the 93 sold is not the same everywhere.

the looks i get at the pump from the attendants. really? 93 in this old car? do as i say sir, thank you......and even then, you need to watch the fool hit the 93 button.

for all you outside NJ we cant pump our own gas. the state thinks we are to dumb i guess lol we are now the last state holding on to this dumb law too. lord knows we could be in and out much faster if we pumped our own fuel, one guy working 4 or more pumps dont work well.

 

[adventurenali92]

If cost is a concern check out Costco/BJ/Sams Club. They only sell 87 and 93. In most cases their 93 is less expensive than the traditional brand name gas companies 91. Just a suggestion.

Our Costco’s and sams clubs out here in California only carry 87 and 91. But that’s a good point, i always get cheaper gas at Costco and it’s a good 20-25 cents cheaper than every other gas station.

 

[PG01]

i learned this with my supercharged regal, one place i got loads of kr, fill up at another kr went away. so now i only get gas at the local BP. clearly the 93 sold is not the same everywhere.

the looks i get at the pump from the attendants. really? 93 in this old car? do as i say sir, thank you......and even then, you need to watch the fool hit the 93 button.

for all you outside NJ we cant pump our own gas. the state thinks we are to dumb i guess lol we are now the last state holding on to this dumb law too. lord knows we could be in and out much faster if we pumped our own fuel, one guy working 4 or more pumps dont work well.

I know, i get yelled at in jersey, im just used to jumping out and doing it. I used to go more often to fill up but since you guys jacked up your taxes, f that noise...

 

[Scottydoggs]

if your in the area its still cheaper. not worth making a trip for it anymore though.

that tax is a load of crap too. it was for the roads and bridges, supposed to add up to billions of dollars. so they write a trick question on the ballots tricking the dummys into voting for the money to spent on all transportation upgrades. i dont ride a train, nor does that train run on gas. wtf? id rather have smooth roads with my tax money.

the kicker is they already borrowed from it for nothing roads related. way to go assholes. now we got that airbag murphy, want to just raise taxes everywhere, says it in the campaign, still gets elected. im all for legal weed, and still voted the other way, sanctuary state, *** off dirt bag.

rant over lol

 

[PNWMuseumman]

i learned this with my supercharged regal, one place i got loads of kr, fill up at another kr went away. so now i only get gas at the local BP. clearly the 93 sold is not the same everywhere.

the looks i get at the pump from the attendants. really? 93 in this old car? do as i say sir, thank you......and even then, you need to watch the fool hit the 93 button.

for all you outside NJ we cant pump our own gas. the state thinks we are to dumb i guess lol we are now the last state holding on to this dumb law too. lord knows we could be in and out much faster if we pumped our own fuel, one guy working 4 or more pumps dont work well.

And then there is Oregon who just took away the pump attendants in the lesser populated counties and everyone freaked the F-out. Citing that only trained individuals should be able to operate the pumps, and that they can't imagine having to get out of their car with homeless people around.

Not sure if you guys caught that online in the last couple weeks. I know in Washington we sure got a good laugh about it.
Hahahahaha

 

[Scottydoggs]

all over the state be like this for months lmao

 

[YD2007]

We own a 2007 Yukon Denali (6.2 - 2nd engine installed around Spring 2016 - Piston #4 was falling apart). There are some steep hills nearby. 87 - 89 - 93 is sold around the Atlanta area - no 91). For both engines, when using 87 going up the hill, if more than 2 people and lots of fuel in the tank, you'll hear a bit of knocking/pinging; almost no noise using 89, and no noise at all using 93. We'll use 87 if we're not planning on doing any heavy hauling, or an 87-89 mix.

My manual says "use premium unleaded gas with a posted octane rating of 91 or higher. You can also use regular unleaded gas rated at 87 octane or higher, but your vehicle's acceleration could be slightly reduced, and you might notice a slight audible knocking noise [we sometimes do]... . If the octane is less than 87, you might notice a heavy knocking noise... . [87 is the lowest available and the lowest we've ever used] . If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. Otherwise, you could damage the engine."

Sometimes we go on a 4-5 hour one-way trip, and we'll use 93 - there are some very steep hills around Chattanooga.

if you're really low on $$ and not pulling much, 87 will be fine, but the engine loves 93...as I said earlier, 91 is not sold around Atlanta (for the most part).

Dave H.