09-16-2022, 11:56 AM
|
#46
|
Member
|
|
Join Date: May 2005
Location: Bellevue, WA
Posts: 232
|
|
Member
Join Date: May 2005
Location: Bellevue, WA
Posts: 232
|
Quote:
Originally Posted by Charles Bronson
With respect to premium resulting in better driving and mpgs in these trucks, I'll just say that the power of suggestion is a very powerful thing to one's mind.
I've seen this discussion/debate time and time again on the automotive forums I've been a part of since the days of dial-up and America Online (AOL).
It really makes no sense for the truck to have better throttle response and less downshifting running premium. Octane is a fuel's resistance to burn. Thus, higher octane fuels are more resistant to burn which is why they are required in motors with really high cylinder pressures. The current gen 1-GR isn't that motor. Plus, the benefits of higher octane would be present under hard, high rpm driving, and not low rpms or initial throttle tip-in.
As for downshifting, that is all related to engine vacuum and load and not octane. The transmission ECU senses a change in engine vacuum and/or load (i.e., higher load) and will downshift accordingly. It has nothing to do with octane.
If someone wants to really put this to the test. Take your 4Runner to a shop with a Dynojet dyno. Do 3 runs with 91 for about $100. Then full up with 87 and run that for a week or so and re-dyno on the same dyno and similar ambient conditions. I would bet the HP and TQ numbers across all runs would all be within 1-2% of each other which is typical dyno run variability.
Lastly, the higher the altitude you are, the less octane the motor needs (low oxygen in the air). That's why in high elevation areas you routinely see 85 octane fuel at pumps. It's not because the stations are "cheap".
|
Oh I've been on the same journey and had the same reaction. A few notes -- again 100% agree this is not data. We're just guessing.
For me: my slow ass truck can now more easily make it over the hill to work (freeway) without any dramatic downshifting. I drive this route every day. Nothing else changed. why? who the hell knows.
I can guess:
- I have heard folks say these engines can ping at low RPM. When the knock sensors detect pre-detonation they retard timing. Retarding timing lowers power/torque. So, if this is simply avoiding the engine retarding timing at low RPMs then this makes sense. We're talking 2-3k rpm here. I wouldn't be surprised at all to see an improvement in low-RPM "tip-in" in this scenario. A dyno run which typically only runs 3+ KRPM isn't going to pick this up.
- Transmissions and downshifting have changed a bit in the last decade. Our throttle pedal is a torque request and this interacts w/the transmission in terms of whether the ECU thinks it can make good on the torque request in current gear. If not, downshift. This is why i've found that ecu tuning boosted engines with automatics (modern) plays hell on shift points and makes the transmissions feel much "lazier". Happier to write much more on this separately.
Anyhow. Hooray: my truck can make it over the "hill" to work without reminding me every single day how gutless it is. The only thing that changed was the fuel. BTW I started this before the weather changed here in Seattle, so -- no -- it isn't colder/denser air
__________________
'22 4runner Limited (ORP 17s)
'18 MacanS (wife's)
'10 997S
|
|
Reply With Quote
|
09-16-2022, 01:41 PM
|
#47
|
Junior Member
|
|
Join Date: Aug 2022
Location: Mississauga
Posts: 17
|
|
Junior Member
Join Date: Aug 2022
Location: Mississauga
Posts: 17
|
Quote:
Originally Posted by 97BlackAckCL
I've been running premium for 5 years and feel like the truck just drives better with it. Granted my ECU is now tuned to run on 93 and the power gain is extremely noticeable, but after a few tanks of 87 when I bought the truck I felt that the gas mileage and overall performance of the truck was always better on 93. To each their own
|
Hmm, where can one get this tune? I am new owner of a 4 Runner and would sell my kidney for a good tune.
|
|
Reply With Quote
|
09-18-2022, 11:22 PM
|
#48
|
|
Elite Member
|
|
Join Date: Mar 2010
Location: Pittsburgh
Posts: 5,686
Real Name: Chris
|
|
Elite Member
Join Date: Mar 2010
Location: Pittsburgh
Posts: 5,686
Real Name: Chris
|
Quote:
Originally Posted by sympley76
Hmm, where can one get this tune? I am new owner of a 4 Runner and would sell my kidney for a good tune.
|
Here's the one I got, highly recommend it
VR Tuned ECU Flash Tune Toyota 4Runner Dual VVT-I 270HP | VRT-TOY-4RN-270
__________________
2017 Nautical Blue SR5 Premium - Black Emblems, AFE 76mm TB, AFE Momentum GT Intake, URD MAF Calibrator, Borla Touring Cat-Back Exhaust, VR ECU Tune, RCI Skid Plate, Morimoto MLED 2.0 Headlight Retrofit, Morimoto LED Fogs, Eagle Eye Smoked Black Tail Lights, FyreFlys LED Interior, Meso Puddle Lights, Tinted Mirror Turn Signals, Smoked Amber Raptor Lights, Odyssey 34 Battery, 32" LED Bar with Rago Hidden Brackets, Rago Molle Panels, Side Shooter LED Ditch Lights, sPod w/ PowerTray, Raceline Matte Bronze Wheels w/ Cooper Discoverer RTX, CaliRaised Rock Sliders, BajaRack Full Length Roof Rack, Kenwood DMX1057XR, Infinity Kappa Door Speakers and 3.5's in dash, JL 8w3v3 in JBL Enclosure, Husky Weather Beaters, Blackvue DR900S Dash Cams
|
|
Reply With Quote
|
09-21-2022, 06:48 PM
|
#49
|
Member
|
|
Join Date: May 2004
Location: Wilmington, NC
Posts: 364
|
|
Member
Join Date: May 2004
Location: Wilmington, NC
Posts: 364
|
I'm not sure why some folks are finding it so hard to believe the 4Runner produces more power with higher octane fuel. It's probably true for most modern engines with an ECU that can adjust timing. It's just the reverse of a Porsche/Ferrarri/Lambo/etc. reducing timing to protect itself if you feed it less than the high octane it's optimized for.
An insider leaked HP numbers for the 2.7 Ecoboost in the Bronco before official numbers were published. Ford only recommends 87 for that motor, but they do publish official output ratings for both 87 and 91 octane...with 91 octane producing an extra 15hp due to the ECU being able to advance timing with 91. What I find interesting...the insider leaked numbers actually showed a 30hp difference...the final official rating increased the 87 octane number while the 91 stayed the same.
So, there's definitely more to it than wishful thinking or placebo. Watch an episode of Engine Power this weekend and see what playing with just timing does to a carbureted engine.
__________________
2003-2022: '03 Limited V8 4x4 - Galactic Gray Mica
2022-Present: '21 Nightshade 4x4 - Magnetic Gray Metallic
|
|
Reply With Quote
|
09-21-2022, 07:25 PM
|
#50
|
|
Member
|
|
Join Date: Jul 2018
Location: Socal
Posts: 560
|
|
Member
Join Date: Jul 2018
Location: Socal
Posts: 560
|
Quote:
Originally Posted by mrblah
i get 10.5 mpg on mixed driving.....
i gave up trying to get better gas mileage a long time ago...
|
Jeez and I thought I was bad with 13.5
I recently got tuned and I am curious to see how my butt dyno and mpg change with octane.
|
|
Reply With Quote
|
09-21-2022, 08:55 PM
|
#51
|
Junior Member
|
|
Join Date: Aug 2022
Location: Mississauga
Posts: 17
|
|
Junior Member
Join Date: Aug 2022
Location: Mississauga
Posts: 17
|
Quote:
Originally Posted by 97BlackAckCL
|
Thank you for the info. This is great.
|
|
Reply With Quote
|
10-31-2022, 07:29 PM
|
#52
|
Member
|
|
Join Date: May 2005
Location: Bellevue, WA
Posts: 232
|
|
Member
Join Date: May 2005
Location: Bellevue, WA
Posts: 232
|
Wanted to share a few more thoughts here after a good, long drive today. This was a fairly rare opportunity for me to get the 4runner out for a long freeway drive. This is a route I know well. Driven it >100 times (back and forth to parent's house). About 200mi round trip. Mostly freeway. Some hills; some traffic.
After today's run, i'm becoming more convinced that our 4runners do have more low-end power on premium. On regular mine is a total dog at 2k RPM on the freeway. Can't deal with a wind gust without downshifting. Today I was running at 70-80mph; flat, hills, accelerating (slowly) on hills, all without downshifting (with premium). Has really changed the drivability of the truck. It's gone from a huge irritant to something that is "still slow, but livable". The powerband that matters in this case is 1.5k - 3k RPM. I'm nearly certain our truck pulls a lot of timing on Regular when you lean into the throttle at these RPMs. Less ping == more timing advance == more power. I could care less about the power at the upper rev ranges. It's plenty but it's a painful sound that I don't want to hear too often
YMMV. Unscientific. Etc. I'm not motivated to spend more money on gas here, but this has turned out to be a significant game changer for me.
__________________
'22 4runner Limited (ORP 17s)
'18 MacanS (wife's)
'10 997S
|
|
Reply With Quote
|
11-01-2022, 05:59 PM
|
#53
|
Member
|
|
Join Date: Aug 2020
Location: Earth
Posts: 295
|
|
Member
Join Date: Aug 2020
Location: Earth
Posts: 295
|
Quote:
Originally Posted by riverwolf
I'm not sure why some folks are finding it so hard to believe the 4Runner produces more power with higher octane fuel. It's probably true for most modern engines with an ECU that can adjust timing. It's just the reverse of a Porsche/Ferrarri/Lambo/etc. reducing timing to protect itself if you feed it less than the high octane it's optimized for.
An insider leaked HP numbers for the 2.7 Ecoboost in the Bronco before official numbers were published. Ford only recommends 87 for that motor, but they do publish official output ratings for both 87 and 91 octane...with 91 octane producing an extra 15hp due to the ECU being able to advance timing with 91. What I find interesting...the insider leaked numbers actually showed a 30hp difference...the final official rating increased the 87 octane number while the 91 stayed the same.
So, there's definitely more to it than wishful thinking or placebo. Watch an episode of Engine Power this weekend and see what playing with just timing does to a carbureted engine.
|
Late turbo tuning strategy is VASTLY different from naturally aspirated motor tuning strategy and power left on the table. With a turbo motor, it is extremely easy to manipulate power/torque, largely through wastegate tuning (i.e., boost production). It's why turbos are so fantastic at altitude. ECUs in most turbo motors these days calculate engine load vs boost being delivered. At altitude, there is less oxygen in the air so when the ECU sees that there is less load vs boost, it increases boost to compensate and meet power targets. With that tuning strategy, a 500hp motor makes nearly all it's 500hp at 5000' elevation vs a naturally aspirated motor that is down about 10%+ of it's power and with no way to correct for it. Load based tuning is also why turbo motors enjoy higher octane fuels and generate wildly different power numbers between using 87, 91, 93, and ethanol fuels.
It is nearly impossible to "add" power to most any naturally aspirated motor by simply giving it more octane than what it was designed to run on. There's just nothing really to take advantage of.
Also, naturally aspirated motors tend not to generate high load at low and mid rpms unlike a turbo motor can that go into very high load at low rpms if driver mashes the gas, thus basically creating a massive amount boost (and torque) because the engine load pushes the turbo into overdrive (i.e., overboost). Naturally aspirated motors can't do this. They might ping and knock around a bit, but that's it. Most naturally aspirated that require higher octane fuels tend to be motors designed to live in the high rpms and have higher compression ratios. 4.0 V6 in the 4Runner is NOT that type of motor LOL
|
|
Reply With Quote
|
Thread Tools |
|
Display Modes |
Rate This Thread |
Linear Mode
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is On
|
|
|
|