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87 octane vs 91 octane

Discussion in 'General Tundra Discussion' started by scturndra, Aug 29, 2016.

  1. Aug 29, 2016 at 1:33 PM

    scturndra [OP] New Member

    Jan 15, 2016
    First Name:
    2012 tundra extra cab sr5 4.6v8
    I have a 2012 tundra 4.6 v8. I have a buddy that has a 2006 tundra with the bigger v8(not sure if it was a 5.7 or not back then) Anyway he told me I needed to run 1 tank every three months of the 91 octane. I bought this truck brand new and have always ran 87, but he is telling me that 91 will help "clean it out" and make it have more horse power while towing.

    Sounds funny but at the same time 91 has a higher octane, but not that much so if its true I am not sure you would really notice.......

    what do you think?
  2. Aug 29, 2016 at 3:57 PM

    bandit New Member

    Mar 6, 2016
    2011 Supercharged Mazzulla Long Travel Rock Warrior
    Duh Tundra
    Higher octane will actually produce more carbon and build up in your motor. All grades of octane contain cleaning detergents. If your truck is not tuned for it you will gain absolutely no benefit from it. Just an old wise tale. Here's the breakdown if you're curious as to the why's. In any sense, don't put 91 in your motor. If you are looking for more hp, add a supercharger and a trd tune. Then, you will need to run 91. Hope this helps and saves you some money, educate your friend too while you're at it. :)

    The Low-Down on High Octane Gasoline

    Are you tempted to buy a high octane gasoline for your car because you want to improve its performance? If so, take note: the recommended gasoline for most cars is regular octane. In fact, in most cases, using a higher octane gasoline than your owner's manual recommends offers absolutely no benefit. It won't make your car perform better, go faster, get better mileage or run cleaner. Your best bet: listen to your owner's manual.

    The only time you might need to switch to a higher octane level is if your car engine knocks when you use the recommended fuel. This happens to a small percentage of cars.

    Unless your engine is knocking, buying higher octane gasoline is a waste of money, too. Premium gas costs 15 to 20 cents per gallon more than regular. That can add up to $100 or more a year in extra costs. Studies indicate that altogether, drivers may be spending hundreds of millions of dollars each year for higher octane gas than they need.

    What are octane ratings?

    Octane ratings measure a gasoline's ability to resist engine knock, a rattling or pinging sound that results from premature ignition of the compressed fuel-air mixture in one or more cylinders. Most gas stations offer three octane grades: regular (usually 87 octane), mid-grade (usually 89 octane) and premium (usually 92 or 93). The ratings must be posted on bright yellow stickers on each gasoline pump.

    What's the right octane level for your car?

    Check your owner's manual to determine the right octane level for your car. Regular octane is recommended for most cars. However, some cars with high compression engines, like sports cars and certain luxury cars, need mid-grade or premium gasoline to prevent knock.

    How can you tell if you're using the right octane level? Listen to your car's engine. If it doesn't knock when you use the recommended octane, you're using the right grade of gasoline.

    Will higher octane gasoline clean your engine better?

    As a rule, high octane gasoline does not outperform regular octane in preventing engine deposits from forming, in removing them, or in cleaning your car's engine. In fact, the U.S. Environmental Protection Agency requires that all octane grades of all brands of gasoline contain engine cleaning detergent additives to protect against the build-up of harmful levels of engine deposits during the expected life of your car.

    Should you ever switch to a higher octane gasoline?

    A few car engines may knock or ping - even if you use the recommended octane. If this happens, try switching to the next highest octane grade. In many cases, switching to the mid-grade or premium-grade gasoline will eliminate the knock. If the knocking or pinging continues after one or two fill-ups, you may need a tune-up or some other repair. After that work is done, go back to the lowest octane grade at which your engine runs without knocking.

    Is knocking harmful?

    Occasional light knocking or pinging won't harm your engine, and doesn't indicate a need for higher octane. But don't ignore severe knocking. A heavy or persistent knock can lead to engine damage.

    Is all "premium" or "regular" gasoline the same?

    The octane rating of gasoline marked "premium" or "regular" is not consistent across the country. One state may require a minimum octane rating of 92 for all premium gasoline, while another may allow 90 octane to be called premium. To make sure you know what
    Viper3G and csuviper like this.
  3. Aug 29, 2016 at 4:09 PM

    joonbug just bacon...

    Oct 13, 2015
    First Name:
    NorCal - Dublin
    2015 Tundra DC 5.7 TRD off-road
    I doubt there would be any noticeable difference. But at about $20 a year, it wouldn't hurt to try it. Personally, I've always just ran 87 and was stuck on 14.5 mpg via computer. I accidentally put in 91 one time and immediately it jumped to over 15 mpg by the end of the tank. And ever since has been steadily climbing to around 15.5. Coincidence? No idea. So now, every once in a while when I get gas for my dirt bike, I'll put in 91. It's more so I don't have to walk up to the cashier two separate times to pay because I'm a very lazy human being, but if it's also helping gas mileage... it's a bonus.
    SuperSilverTundra likes this.
  4. Aug 29, 2016 at 6:26 PM

    CaptTyler www.fishcharlotteharbor.com

    Jul 23, 2015
    First Name:
    Punta Gorda, FL
    2012 MGM Crewmax
    Bilstein 5100's F&R +2 CB Shims CB +2 Shackles 295-65-20 Toyo AT2 BAMuffler 7" Spidertrax 1.25" G-Tek SABM / aFe Pro Dry S (Charcoal Delete) Husky X-ACT Floor Mats All LED Interior / Reverse Lights / Cargo Lights Philips Xtreme Vision Headlights
    I've always ran 87.
    The one thing I always do is buy my gas from only Shell or Chevron (Top Tier gasoline.)
  5. Aug 31, 2016 at 7:13 AM

    Skidmarks New Member

    Jun 3, 2016
    I think it makes sense that your MPG increased due to the fact that the higher octane fuel was designed to decrease "knock". This would slow down pre-ignition and increasing efficiency.
    However if you add higher octane hoping to clean your engine you are wasting your money " as bandit said" because all 3 octane levels have the exact same detergents for cleaning.
    The octane rating is a measure of a fuel’s ability to avoid knock. Knock occurs when fuel is prematurely ignited in the engine’s cylinder, which degrades efficiency and can be damaging to the engine. Knock is virtually unknown to modern drivers. This is primarily because fuels contain an oxygenate that prevents knock by adding oxygen to the fuel. This oxygenate is commonly referred to as octane.
    At most retail gasoline stations, three octane grades are offered, 87 (regular), 89 (mid-grade), and 91-93 (premium). The higher the octane number, the more resistant the gasoline mixture is to knock. The use of higher octane fuels also enables higher compression ratios, turbocharging, and downsizing/downspeeding—all of which enable greater engine efficiencies and higher performance.
    bandit and rideandfly like this.
  6. Aug 31, 2016 at 12:21 PM

    bobeast really old member

    Feb 11, 2015
    First Name:
    Hollister, CA
    2008 DC
    - Bull Bar - LED Bunny Burners - AMP retractable running boards - Headlight leveling retrofit - P3 Brake Controller - 60% rear seat delete - relocation of Sub to rear wall - Bilstein 5100 x4, top setting with 2 shims per side - Coach builder +2 rear shackles w/carrier bearing drop - Firestone Air bags - on-board compressor with auto-leveling - Dual Undercover Swing Boxes. - P285/65/R20 (34.6") BFG TA KO2's - TRD Front skid plate - Pop & Lock Tailgate lock - Remote Tailgate mod - LED Headlights - Nav Bypass - iPhone integration - Serius/XM retrofit - 25% front tint - Bizon electric tonneau cover - Power folding tow mirror upgrade - 2010+ leveling Headlight mod - Auto-fold mirror mod. - one-touch lane changer mod - Flash to open garage opener mod - Rigid H/L fog light upgrade - Pushbutton / Remote start mod.
    Who ya' gonna believe? Your buddy or your manual?
  7. Aug 31, 2016 at 12:34 PM

    csuviper Moderator Staff Member

    Jan 6, 2014
    First Name:
    Broomfield, CO
    2012 Rock Warrior 5.7L 4X4
    Some Mods :) See build thread for details
    Manual says 87. 87 is what the truck runs off best. 87 is what i run.

    I have tried 91 with no change in performance or gas mileage.
    bandit, matluth and ColoradoTJ like this.

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