1. Welcome to Tacoma World!

    You are currently viewing as a guest! To get full-access, you need to register for a FREE account.

    As a registered member, you’ll be able to:
    • Participate in all Tacoma discussion topics
    • Communicate privately with other Tacoma owners from around the world
    • Post your own photos in our Members Gallery
    • Access all special features of the site

87 vs 91

Discussion in '2nd Gen. Tacomas (2005-2015)' started by nd, Mar 22, 2007.

  1. Mar 22, 2007 at 7:08 AM
    #1
    nd

    nd [OP] Radical Town. It's a hell of a place!

    Joined:
    Mar 12, 2007
    Member:
    #1047
    Messages:
    12,619
    Gender:
    Male
    First Name:
    Nate
    Greenville, SC
    Vehicle:
    07 TRD Off-Road 4x4 debadged
    De badged, 5100's, Black Toyota Baja wheels
    Hey everyone, this is my first aside from my introduction. I have a quick question. When researching 2nd gen tacomas, this biggest complaint i found was that the 05 and 06 models with V6 run on premium gas, and the performance suffers greatly if you use the cheap stuff. I just recently bought an 07 and was told it was ok to use the cheap stuff. I have filled her up with 87 and 91 to see if i could tell a difference. I was wondering if anyone had any feedback on the subject. Also, there is a loss of about 10hp and 15ft/tq from 06 to 07, is this explained by the ability to run on cheaper fuel? Any feedback would be appreciated. Thanks
     
  2. Mar 22, 2007 at 8:07 AM
    #2
    TRDeity

    TRDeity Well-Known Member

    Joined:
    Jan 24, 2007
    Member:
    #774
    Messages:
    461
    ATX
    Vehicle:
    2017 TRDpro
  3. Mar 22, 2007 at 9:58 AM
    #3
    CasaTaco

    CasaTaco Active Member

    Joined:
    Jan 19, 2007
    Member:
    #748
    Messages:
    41
    My wife's Lexus RX300 operators manual also says to use Premium fuel. We've been using Regular for about 94,000 miles now.
     
  4. Mar 22, 2007 at 10:00 AM
    #4
    tcBob

    tcBob Gringo Bandito Moderator

    Joined:
    Sep 6, 2006
    Member:
    #1
    Messages:
    15,475
    Gender:
    Male
    First Name:
    Bob
    Vehicle:
    07 PreRunner SR5 V6 Black
    Someone at my dealership was saying you're better off using the cheaper stuff because it doesn't make any difference in the Tacoma.
     
  5. Mar 24, 2007 at 5:11 AM
    #5
    TacoMan

    TacoMan Active Member

    Joined:
    Mar 7, 2007
    Member:
    #1017
    Messages:
    27
    My mom's maxima is supposed to have premium according to the owners manual as well. They ran 87 in it for over 80,000 miles. Then they had a problem with a computer component that affects the timing. They were told they had the problem because they ran a low octane fuel and the car had to compensate for it for too long a period, and that it would normally be okay to run 87 every now and then. It's just the car was designed to use premium. Anyway it was not a dealer and there was no warranty by that time, so my folks felt there was no reason the mechanic would have to shift blame. I plan on driving my truck for a long long time, so I run the premium as the book suggests.

    Compression usually has a deciding factor of what you should run, does anyone know what our compression is?
     
  6. Mar 24, 2007 at 2:05 PM
    #6
    tacomax

    tacomax Member

    Joined:
    Nov 16, 2006
    Member:
    #244
    Messages:
    14
    on the I4 is 9.6:1
    the 4.0L V6 is 10:1

    I utilized 91 and higher on my 05 prerunner from the beginning then tried 87 when prices were high and did noticed a slight pinging noise on hard acceleration or steep climbs..so I just stick with 91>

    High octane fuel has more potential energy but needs higher heat created by a higher compression engine to properly condition the fuel to release that higher potential energy

    from what i have read before on engines with compression ratios of 9.0 : 1 or less you can use unleaded 87 octane fuel. Engines with higher compression ratios usually require higher octane fuels.

    when fuel octane is too low for a given compression ratio, the fuel ignites prematurely, too early, and the fuel charge explodes instead of burning thus resulting in an incomplete combustion. so the engine tends to lose power and may cause engine damage. When you hear that knock or pinging, or even detonation, which may vary from a faint noise on light acceleration to a constant, deep hammering noise while driving at a constant speed. bad timing adjustments, vacuum leaks, or excessively lean fuel mixtures can too cause detonation...
     
    Tacoma HEART likes this.
  7. Nov 24, 2016 at 8:57 AM
    #7
    Pigpen

    Pigpen My truck is never clean

    Joined:
    Mar 6, 2012
    Member:
    #74319
    Messages:
    8,963
    Gender:
    Male
    Northwest Montana
    Vehicle:
    2012 AC Manual 4.0 4x4 Base Model
    Access cab toolbox/ dog bed with seats and headrests deleted, waterproof TRD seat covers, yellow wire mod, diff breather relocated to tail light, engine block heater, Leer topper with Yakima tracks and rack, Yakima rack on cab, Ride Rite with Daystar cradles, CBI hidden front hitch, wired for winch front and rear Warn quick connect, Warn x8000i on external carrier, sway bar delete, trailer plug relocated to bumper, Pelfreybilt IFS and Mid skids, ECGS front diff bushing, ARB CKMA12 compressor, 255/85/16 Backcountrry MT 3 load E tires on stock steel rims, Up2NoGood heated mirror kit, Husky X-act Contour front floor liners, Northstar AGM 24F battery, Pelfreybilt bolt on sliders with kickout and top plates, TRD Pro headlights, Depo smoked tail lights, Energy suspension body mount bushing kit, OME Dakar leaf packs with AAL, Billstein B110 rear shocks, OME 90021 front shocks with 885 coils, SPC LR UCAs, Up2NoGood 2wd low range mod, 4 Wheel Campers Grandby slide in camper
  8. Nov 24, 2016 at 9:00 AM
    #8
    Sub_Par

    Sub_Par Well-Known Member

    Joined:
    Nov 17, 2015
    Member:
    #169939
    Messages:
    4,074
    Gender:
    Male
    First Name:
    Steve
    Buffalo NY
    Vehicle:
    2011 TRD Off Road
    Feeling bored? Trying to start something today?
     
    DustStorm4x4 likes this.
  9. Nov 24, 2016 at 9:27 AM
    #9
    Pigpen

    Pigpen My truck is never clean

    Joined:
    Mar 6, 2012
    Member:
    #74319
    Messages:
    8,963
    Gender:
    Male
    Northwest Montana
    Vehicle:
    2012 AC Manual 4.0 4x4 Base Model
    Access cab toolbox/ dog bed with seats and headrests deleted, waterproof TRD seat covers, yellow wire mod, diff breather relocated to tail light, engine block heater, Leer topper with Yakima tracks and rack, Yakima rack on cab, Ride Rite with Daystar cradles, CBI hidden front hitch, wired for winch front and rear Warn quick connect, Warn x8000i on external carrier, sway bar delete, trailer plug relocated to bumper, Pelfreybilt IFS and Mid skids, ECGS front diff bushing, ARB CKMA12 compressor, 255/85/16 Backcountrry MT 3 load E tires on stock steel rims, Up2NoGood heated mirror kit, Husky X-act Contour front floor liners, Northstar AGM 24F battery, Pelfreybilt bolt on sliders with kickout and top plates, TRD Pro headlights, Depo smoked tail lights, Energy suspension body mount bushing kit, OME Dakar leaf packs with AAL, Billstein B110 rear shocks, OME 90021 front shocks with 885 coils, SPC LR UCAs, Up2NoGood 2wd low range mod, 4 Wheel Campers Grandby slide in camper
    :D
     
    DustStorm4x4 likes this.
  10. Nov 24, 2016 at 9:30 AM
    #10
    DustStorm4x4

    DustStorm4x4 BBC 2020

    Joined:
    Jul 2, 2015
    Member:
    #158634
    Messages:
    8,934
    Gender:
    Male
    U S A
    Vehicle:
    04 Jeep LJ
    Evil :stirthepot:
     
  11. Nov 24, 2016 at 9:51 AM
    #11
    Pigpen

    Pigpen My truck is never clean

    Joined:
    Mar 6, 2012
    Member:
    #74319
    Messages:
    8,963
    Gender:
    Male
    Northwest Montana
    Vehicle:
    2012 AC Manual 4.0 4x4 Base Model
    Access cab toolbox/ dog bed with seats and headrests deleted, waterproof TRD seat covers, yellow wire mod, diff breather relocated to tail light, engine block heater, Leer topper with Yakima tracks and rack, Yakima rack on cab, Ride Rite with Daystar cradles, CBI hidden front hitch, wired for winch front and rear Warn quick connect, Warn x8000i on external carrier, sway bar delete, trailer plug relocated to bumper, Pelfreybilt IFS and Mid skids, ECGS front diff bushing, ARB CKMA12 compressor, 255/85/16 Backcountrry MT 3 load E tires on stock steel rims, Up2NoGood heated mirror kit, Husky X-act Contour front floor liners, Northstar AGM 24F battery, Pelfreybilt bolt on sliders with kickout and top plates, TRD Pro headlights, Depo smoked tail lights, Energy suspension body mount bushing kit, OME Dakar leaf packs with AAL, Billstein B110 rear shocks, OME 90021 front shocks with 885 coils, SPC LR UCAs, Up2NoGood 2wd low range mod, 4 Wheel Campers Grandby slide in camper
    I pretty much strictly run 87. The 91 here is ethanol free. Ethanol has more energy in it, so I get more horse power as well as better mpg.
     
  12. Nov 24, 2016 at 10:13 AM
    #12
    Lthompson

    Lthompson Well-Known Member

    Joined:
    Mar 13, 2016
    Member:
    #181136
    Messages:
    936
    Gender:
    Male
    Never heard of ANYONE getting better mileage with ethanol. have you ever actually tested your theory? because ive seen the opposite MANY times.. its technically considered a higher octane rating, but it takes more of it to reach that, or something.. Not sure. But, You don't get more horsepower out of it.. You can "get" more horsepower out of e85, because it burns cooler, therefore allowing you to add boost, or compression, and increase timing without adverse effects, but mileage GREATLY suffers. Ethanol really isn't good for anything, and I run ethanol free in EVERYTHING, because Ive seen 2-3 mpg better using it. Oh, and don't ever run ethanol in lawn mowers or ATVs or anything that sits unused for any amount of time. It will ruin it
     
  13. Nov 24, 2016 at 10:15 AM
    #13
    Pigpen

    Pigpen My truck is never clean

    Joined:
    Mar 6, 2012
    Member:
    #74319
    Messages:
    8,963
    Gender:
    Male
    Northwest Montana
    Vehicle:
    2012 AC Manual 4.0 4x4 Base Model
    Access cab toolbox/ dog bed with seats and headrests deleted, waterproof TRD seat covers, yellow wire mod, diff breather relocated to tail light, engine block heater, Leer topper with Yakima tracks and rack, Yakima rack on cab, Ride Rite with Daystar cradles, CBI hidden front hitch, wired for winch front and rear Warn quick connect, Warn x8000i on external carrier, sway bar delete, trailer plug relocated to bumper, Pelfreybilt IFS and Mid skids, ECGS front diff bushing, ARB CKMA12 compressor, 255/85/16 Backcountrry MT 3 load E tires on stock steel rims, Up2NoGood heated mirror kit, Husky X-act Contour front floor liners, Northstar AGM 24F battery, Pelfreybilt bolt on sliders with kickout and top plates, TRD Pro headlights, Depo smoked tail lights, Energy suspension body mount bushing kit, OME Dakar leaf packs with AAL, Billstein B110 rear shocks, OME 90021 front shocks with 885 coils, SPC LR UCAs, Up2NoGood 2wd low range mod, 4 Wheel Campers Grandby slide in camper
    Drag racers run ethanol, and my butt dyno says the truck has more power.
     
  14. Nov 24, 2016 at 10:18 AM
    #14
    Lthompson

    Lthompson Well-Known Member

    Joined:
    Mar 13, 2016
    Member:
    #181136
    Messages:
    936
    Gender:
    Male
    that being said, I usually run 91 in mine.. because its ethanol free. I recently ran some 93, and mileage seems to have dropped. Which makes sense, the higher the octane rating, the more resistant it is to explosion.. or, the less volatile.. Therefore it doesn't burn well if it doesn't have enough heat and ignition. It also has a lower stoich ratio, which means it runs richer to reach optimum A/F ratio
     
  15. Nov 24, 2016 at 10:19 AM
    #15
    Lthompson

    Lthompson Well-Known Member

    Joined:
    Mar 13, 2016
    Member:
    #181136
    Messages:
    936
    Gender:
    Male
    I explained why racers run E85. But they aren't concerned about mileage either.
     
  16. Nov 24, 2016 at 10:22 AM
    #16
    Lthompson

    Lthompson Well-Known Member

    Joined:
    Mar 13, 2016
    Member:
    #181136
    Messages:
    936
    Gender:
    Male
    If it works for you then great, because you can get it everywhere. Some states actually have laws against selling ethanol free. But I do my best not to run it
     
  17. Nov 24, 2016 at 10:26 AM
    #17
    Pigpen

    Pigpen My truck is never clean

    Joined:
    Mar 6, 2012
    Member:
    #74319
    Messages:
    8,963
    Gender:
    Male
    Northwest Montana
    Vehicle:
    2012 AC Manual 4.0 4x4 Base Model
    Access cab toolbox/ dog bed with seats and headrests deleted, waterproof TRD seat covers, yellow wire mod, diff breather relocated to tail light, engine block heater, Leer topper with Yakima tracks and rack, Yakima rack on cab, Ride Rite with Daystar cradles, CBI hidden front hitch, wired for winch front and rear Warn quick connect, Warn x8000i on external carrier, sway bar delete, trailer plug relocated to bumper, Pelfreybilt IFS and Mid skids, ECGS front diff bushing, ARB CKMA12 compressor, 255/85/16 Backcountrry MT 3 load E tires on stock steel rims, Up2NoGood heated mirror kit, Husky X-act Contour front floor liners, Northstar AGM 24F battery, Pelfreybilt bolt on sliders with kickout and top plates, TRD Pro headlights, Depo smoked tail lights, Energy suspension body mount bushing kit, OME Dakar leaf packs with AAL, Billstein B110 rear shocks, OME 90021 front shocks with 885 coils, SPC LR UCAs, Up2NoGood 2wd low range mod, 4 Wheel Campers Grandby slide in camper
    I also like the idea of burning less petroleum because it's better for the environment to burn ethanol than petroleum.
     
  18. Nov 24, 2016 at 10:31 AM
    #18
    Lthompson

    Lthompson Well-Known Member

    Joined:
    Mar 13, 2016
    Member:
    #181136
    Messages:
    936
    Gender:
    Male
    Pure gas burns around 14.7 stoich A/F. E10 burns around 14-14.1. It burns richer, therefore requiring more fuel to the same amout of air.. Sometimes a little more fuel can create a little more power. But at the sacrifice of efficiency. E85 burns around 9.7 stoich. So it burns really rich
     
  19. Nov 24, 2016 at 10:32 AM
    #19
    Tacoma HEART

    Tacoma HEART - - - - - - -

    Joined:
    Jan 11, 2015
    Member:
    #146108
    Messages:
    689
    Gender:
    Male
    First Name:
    Sam
    AA CO
    Vehicle:
    '14 DCSB TRD S Black
    Yawn...
    Just waiting for someone to link that YouTube video of the guy explaining why higher octane really doesn't make much difference. Blah blah blah. It pops up at every one of these discussions... :lalala:

    Ever since purchase in '14, there was only one time I added regular. I noticed some extra sounds when I accelerated and every now and then during idle.

    Went right back to 91 after that and the small noises went away.

    No change in MPG, but I wasn't looking for MPG in the first place.
     
  20. Nov 24, 2016 at 10:35 AM
    #20
    Pigpen

    Pigpen My truck is never clean

    Joined:
    Mar 6, 2012
    Member:
    #74319
    Messages:
    8,963
    Gender:
    Male
    Northwest Montana
    Vehicle:
    2012 AC Manual 4.0 4x4 Base Model
    Access cab toolbox/ dog bed with seats and headrests deleted, waterproof TRD seat covers, yellow wire mod, diff breather relocated to tail light, engine block heater, Leer topper with Yakima tracks and rack, Yakima rack on cab, Ride Rite with Daystar cradles, CBI hidden front hitch, wired for winch front and rear Warn quick connect, Warn x8000i on external carrier, sway bar delete, trailer plug relocated to bumper, Pelfreybilt IFS and Mid skids, ECGS front diff bushing, ARB CKMA12 compressor, 255/85/16 Backcountrry MT 3 load E tires on stock steel rims, Up2NoGood heated mirror kit, Husky X-act Contour front floor liners, Northstar AGM 24F battery, Pelfreybilt bolt on sliders with kickout and top plates, TRD Pro headlights, Depo smoked tail lights, Energy suspension body mount bushing kit, OME Dakar leaf packs with AAL, Billstein B110 rear shocks, OME 90021 front shocks with 885 coils, SPC LR UCAs, Up2NoGood 2wd low range mod, 4 Wheel Campers Grandby slide in camper
    That's good info.

    It would be interesting to hear what experience others are having too.
     

Products Discussed in

To Top