Regular fuel on Premium fuel engine

[Stewie]

So my gf got a 2008 Acura TSX and she told me that she was paying for 91 premium

Could it cause any problems to the engine besides lower HP if regular fuel was used? I know that the knock sensor will adjust but I am not sure if it will increase carbon build or making it run rich.

 

[Doog]

Try it and see....I have about 420,000 accumulated miles on 3 Lexus engines that never saw anything but 87 and they were speced for 91.

 

[Stewie]

Originally Posted By: Doog
Try it and see....I have about 420,000 accumulated miles on 3 Lexus engines that never saw anything but 87 and they were speced for 91.


First owner?

 

[cduarte119]

Should be fine if the owners manual says 87 can be used. I don't think it would cause anymore build up just use a high quality gas like top tier brands.

 

[bbhero]

My Altima is specd for 93 which I have always run in it. I ran some 711 93 in it and it ran terrible. I almost always run Shell 93 in it because the car runs best on it.
My Ford Fusion was specd to run 87. I almost always ran 93 in it. I tried 87 in it one time. Car ran really bad.. Knocking a lot, sputtering upon acceleration. In the manual it stated there could be some light "spark knock" which was nothing to be concerned with. But as bad as the car ran it was not even a question to run the 93 in it. Ran that again and no more spark knock and car ran perfect.
I do believe many applications where 87 is just fine obviously. But I think a car set to run 93 should get it. I ran across a nice lady with the same 3.5 VQ motor in her brand new 2014 Maxima. She said the car was running horribly.. I was like ahh yeah hun. You have to run 93 in it. She was like which one is that?? So, I bet it wasn't running good at all.
But hey, maybe in your case it could work. But as you well know if it idles poorly and knocks\pings a lot under load then maybe not best way to go.

 

[Stewie]

Placebo effect?

For cars specified to use unleaded gas will just do about any gas, I once ran 94 cuz was the same price

and I didn't notice any difference.

After reading through her owner's manual it said it could hinder performance but would do no harm if the octane is equal or greater than 87 which minimum here is 87. As for detergents, almost all gas stations (90%) in

are in the top tier gas program.

 

[Stewie]

For those wondering:


TOP TIER Gasoline Retailers:

USA

76 Stations
Aloha Petroleum
ARCO
Beacon
BP
Chevron
Conoco
Costco Wholesale
CountryMark
Diamond Shamrock
Entec Stations
Express Convenience Centers
Exxon
Hawaii Fueling Network (HFN)
Holiday Stationstores
Kwik Trip / Kwik Star
MFA Oil Co.
Mobil
Ohana Fuels
Phillips 66
QuikTrip
Road Ranger
Shamrock
Shell
Sinclair
Suncor Energy Inc
SuperAmerica
Texaco
Tri-Par Oil Co.
Valero


Canada

Chevron Canada
CO-OP
Costco Wholesale
Esso
Petro-Canada
Shell Canada
Tempo


Puerto Rico

Puma Energy Caribe, LLC
Shell


Deposits control:

http://www.toptiergas.com/deposit_control.html

 

[asiancivicmaniac]

My Nissan's VQ runs poorly on 87 and the gas mileage difference is enough to make 93 not much more expensive per tank than 87.

 

[Stewie]

Originally Posted By: asiancivicmaniac
My Nissan's VQ runs poorly on 87 and the gas mileage difference is enough to make 93 not much more expensive per tank than 87.


Maybe in the

premium and regular are not very far but here it is.

She spends $15 more than me with same mileage.

 

[bbhero]

Ahh no.. Its would be obvious to anyone who remotely pays any attention. Knocking it pinging is obvious at idle or under load. Seriously the Fusion ran like garbage on 87. Only other time it pinged at all.... When plugs needed replacement at 104k miles. That wasn't placebo either. Obvious.
Like the other person stated on here.. The VQ specd for 93 runs WAY better on it. And that lady I ran across at the Shell station with a car with 30 temp tags on it because it was brand new.. Ask her. Even she knew something was dead wrong with her car.
Again, in many cars it is fine for. My lady's Camry is specd for it and runs good on Shell 87. Many others are good too on it.

 

[hpb]

If the manual says 87 is ok, then it should be ok, but probably won't be putting out quite as much power as it should if the computer backs the timing off as it detects pinging. Out of interest, what's the price difference between standard and premium fuel? Our fuel is 91, 95 or 98, and from memory 98 is usually about 20 cents per litre more expensive than 91, so roughly 10 bucks extra per tank.

 

[skyactiv]

Unfortunately, North America gets less efficient and less power engines from the auto makers in Japan and Europe becuase of our love for 87 octane. The European Mazda Skyactiv engine has 1 point higher compression and VW and Mercedes have gone as far to tell Washington our gas sucks.

 

[hpb]

Don't worry, our fuel is rubbish too, and we also get the lower powered versions of certain vehicles. At least your fuel is cheap! Keep in mind too, we use the RON system, you use MON, so our 91 is about equivalent to your 87.

 

[eljefino]

Sometimes you'll see a car advertised with "200 peak horsepower", where the peak is on high-test. Yet for marketing they'll let it detune itself on 87 so it competes cost-wise with other marques.

Don't let an internet ditto board influence you, try both.

 

[montero1]

Originally Posted By: hpb
If the manual says 87 is ok, then it should be ok, but probably won't be putting out quite as much power as it should if the computer backs the timing off as it detects pinging. Out of interest, what's the price difference between standard and premium fuel? Our fuel is 91, 95 or 98, and from memory 98 is usually about 20 cents per litre more expensive than 91, so roughly 10 bucks extra per tank.


It is about .20 difference from 87 octane to 93 octane near me. I usually use 13.5 gallons to fill my Mini, so that would save me $2.70 a tank. I take the middle ground, and use 89 octane, for .10 cheaper... after all, I'm not towing or racing.

 

[seanf]

IMO if you can't feel a difference the only way is to data log knock sensor data and timing pull using regular and premium fuel and see if there is a change, I run premium in all of our Audi's most of the year, the 2 that don't have REVO performance software get 87 octane in the winter and I don't notice any performance difference, just a difference with worse mileage as most of our 91 gas has no ethanol and all of the 87 does have it so I've since decided to just run everything on premium.

 

[Stewie]

Originally Posted By: seanf
IMO if you can't feel a difference the only way is to data log knock sensor data and timing pull using regular and premium fuel and see if there is a change, I run premium in all of our Audi's most of the year, the 2 that don't have REVO performance software get 87 octane in the winter and I don't notice any performance difference, just a difference with worse mileage as most of our 91 gas has no ethanol and all of the 87 does have it so I've since decided to just run everything on premium.


Expensive though

My brother's audi just runs regular

Premium here is bout $.30 more per LITRE not gallon

 

[DAC17]

Originally Posted By: montero1
Originally Posted By: hpb
If the manual says 87 is ok, then it should be ok, but probably won't be putting out quite as much power as it should if the computer backs the timing off as it detects pinging. Out of interest, what's the price difference between standard and premium fuel? Our fuel is 91, 95 or 98, and from memory 98 is usually about 20 cents per litre more expensive than 91, so roughly 10 bucks extra per tank.


It is about .20 difference from 87 octane to 93 octane near me. I usually use 13.5 gallons to fill my Mini, so that would save me $2.70 a tank. I take the middle ground, and use 89 octane, for .10 cheaper... after all, I'm not towing or racing.


You're being falsely thrifty. If the octane difference from 87 to 93 is 6, and you're paying 50% of the price difference for 33% of the octane, you aren't maximizing your benefits. Would be better to alternate 87 and 93 fill-ups. I know I'm talking pennies, but this whole thread is about relatively minor $$ impacts.

 

[OVERKILL]

Originally Posted By: Stewie
Originally Posted By: seanf
IMO if you can't feel a difference the only way is to data log knock sensor data and timing pull using regular and premium fuel and see if there is a change, I run premium in all of our Audi's most of the year, the 2 that don't have REVO performance software get 87 octane in the winter and I don't notice any performance difference, just a difference with worse mileage as most of our 91 gas has no ethanol and all of the 87 does have it so I've since decided to just run everything on premium.


Expensive though

My brother's audi just runs regular

Premium here is bout $.30 more per LITRE not gallon


Does your brother's Audi allow for regular (87)? Yes, gas is expensive. A cracked piston or lifted ring land is a lot more expensive though.

My bimmer has 11:1 compression and calls for 91 octane. So it gets 91 octane. I knew that getting into the car. The Charger allows for 87 or 89, both are acceptable.

Run what the TSX manual lists as acceptable. If that includes 87, you are fine. However, if it specifically states to run 91, run 91.

Otherwise, you are just gambling that the knock sensor is sensitive and responsive enough to stop this from happening:

 

[Stewie]

Originally Posted By: OVERKILL
Originally Posted By: Stewie
Originally Posted By: seanf
IMO if you can't feel a difference the only way is to data log knock sensor data and timing pull using regular and premium fuel and see if there is a change, I run premium in all of our Audi's most of the year, the 2 that don't have REVO performance software get 87 octane in the winter and I don't notice any performance difference, just a difference with worse mileage as most of our 91 gas has no ethanol and all of the 87 does have it so I've since decided to just run everything on premium.


Expensive though

My brother's audi just runs regular

Premium here is bout $.30 more per LITRE not gallon


Does your brother's Audi allow for regular (87)? Yes, gas is expensive. A cracked piston or lifted ring land is a lot more expensive though.

My bimmer has 11:1 compression and calls for 91 octane. So it gets 91 octane. I knew that getting into the car. The Charger allows for 87 or 89, both are acceptable.

Run what the TSX manual lists as acceptable. If that includes 87, you are fine. However, if it specifically states to run 91, run 91.

Otherwise, you are just gambling that the knock sensor is sensitive and responsive enough to stop this from happening:

Oh yeah my brother runs 87 and for gf's TSX it says minimum of 87 octanes we good