GX460 ECM Remapping for Regular Gas? (2 Viewers)
- Thread starter eugarps
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r2m
Richard
Just pour it in!
No remapping required.
For decades I've only used regular gas in both our 100 series Landcruisers and never an issue.
I have to admit that since I've had my GX I do use high octane.
Seriously, I don't think there would be an issue. These motors are pretty bullet proof.
No remapping required.
For decades I've only used regular gas in both our 100 series Landcruisers and never an issue.
I have to admit that since I've had my GX I do use high octane.
Seriously, I don't think there would be an issue. These motors are pretty bullet proof.
- Thread starter
- #3
Thanks r2m,
I'm pretty sure that the highly computerized engine in the 2013 GX460 I'm considering is perfectly capable of sorting out octane deficiencies. Unlike the manual spark advance/retard in my first 1931 Model A Ford, the Lexus will just do it without a murmur or hiccup.
I'm pretty sure that the highly computerized engine in the 2013 GX460 I'm considering is perfectly capable of sorting out octane deficiencies. Unlike the manual spark advance/retard in my first 1931 Model A Ford, the Lexus will just do it without a murmur or hiccup.
DO NOT just put in low octane fuel.
Yes the 460's ECU will pull timing when it sees octane knock but it only has so much ability before it throws a CEL because it knows something is wrong.
You can use as low as 91 (Premium here in CA) and you'll be fine.
Yes the 460's ECU will pull timing when it sees octane knock but it only has so much ability before it throws a CEL because it knows something is wrong.
You can use as low as 91 (Premium here in CA) and you'll be fine.
2013 GX and I have used regular since day one. 20mpg highway and 15-16mpg city. I can detect absolutely no difference in power. I can detect absolutely 30-40 cents per gallon savings.
Relax, you will be fine. The same V8 has been used in the real LC all over the world gulping down tons of sh!t gas with stride. There is a reason our V8 has “antiquated” mechanical clutch fan and no direct injection like the LS. The reason is for reliability in all conditions which includs sh!t gas. There won’t be much of power difference unless it’s WOT which I never do and if driven normal and easy no MPG difference to speak of.
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r2m
Richard
Unless one goes to one of the few gas stations that cell 105 octane racing fuel (there's Unioin 76 station down here in Aliso Viejo that sells 105), in California, the highest common fuel is 91 octane. Not sure if any other states sell any higher octane throughout their state as "premium" fuel. Are there other states that there "premium" is higher than 91 octane?
I suggest you log ignition advance and fuel trims to see the truth behind the 87 vs 91 or you could put it on an actual dyno since we all know that a butt dyno is useless.
You're down about 10bhp and roughly 15 ft/lbs.
It will take at least a tank or two for the ignition multiplier to reset and to get the proper ignition advance for the better fuel.
I didn't say it wouldn't work, there's a chance you'll set a CEL, you lose power and torque, and adversely effect emissions efficiency.
Yes, There is 93 octane available in multiple states.
You're down about 10bhp and roughly 15 ft/lbs.
It will take at least a tank or two for the ignition multiplier to reset and to get the proper ignition advance for the better fuel.
I didn't say it wouldn't work, there's a chance you'll set a CEL, you lose power and torque, and adversely effect emissions efficiency.
Yes, There is 93 octane available in multiple states.
No one here will disagree with you in power lost with lower octane fuel, however if the power lost is not noticeable by butt dyno then there is no perceived power lost. Also the power lost is at WOT not lower RPM range where we normally drive.
Why? Because of VVTI, VVTI kicks in at higher RPM to produce more power and premium fuel needed for when the vvti kicks in to produce maximum amount of power. With low octane fuel the ECU will reduce timing or turn off VVTI since I think our engine has the electrically actuated VVTI/cam as supposed to the older hydraulically actuated cam.
In short, don’t worry about it unless you WOT all the time trying to race rice rockets. 87 won’t hurt a thing or even produce less power especially at lower RPM.
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Your engine sees the most aggressive ignition advance from idle to about 3500rpm, the most significant power loss would be there not WOT. This is done because you can get more torque in the low end to get the car moving so drivers will not stomp on the gas as hard hence improving fuel economy.
With 11.8:1 compression lower octane fuel will knock even if it's not audible knock. This is where WOT worries me because it's an open loop event with a much more aggressive the partial throttle ignition map and knock there can really hurt an engine.
VVTi (active cam timing in not trademarked terms) in the 1UR-FE is always on throughout the RPM range, it's just the amount of advance that varies. VVTi cam timing is reduced it the ecu sees knock events.
Yes the car will run, and yes you probably won't blow up the engine (thanks to Toyota's over conservative tuning) but for $2-$4 (all my local stations are a $0.15 max difference between 87 and 91) a tank?
Why?
With 11.8:1 compression lower octane fuel will knock even if it's not audible knock. This is where WOT worries me because it's an open loop event with a much more aggressive the partial throttle ignition map and knock there can really hurt an engine.
VVTi (active cam timing in not trademarked terms) in the 1UR-FE is always on throughout the RPM range, it's just the amount of advance that varies. VVTi cam timing is reduced it the ecu sees knock events.
Yes the car will run, and yes you probably won't blow up the engine (thanks to Toyota's over conservative tuning) but for $2-$4 (all my local stations are a $0.15 max difference between 87 and 91) a tank?
Why?
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Circling back to this topic. Now that there's a $.70 delta from regular to premium it's a $14 / tank decision - $725 annualized!
So, yes, my wife's mall cruiser's no longer drinking the good stuff she's just getting plain old Shell 87.
So, yes, my wife's mall cruiser's no longer drinking the good stuff she's just getting plain old Shell 87.
re_guderian
SILVER Star
87, no worries...
Bear in mind while other markets allow for lower octane… they also have lower output… IIRC most foreign 460 brochures list 292HP versus 301.
re_guderian
SILVER Star
Agreed, but it's a nit in terms of 350 extra pounds of steel bumpers, winch, sliders, skids, wider, taller tires, and worse aerodynamics with a lift. Plus, some of us drove 2F powered Land Cruisers, which weighed about the same as the GX, and rolled off the assembly line with a whopping 135 HP on a good day. If 9 extra HP is make or break, you're in the wrong type of car...
I've often wanted to see the intakes (from throttle body to valves) of the same vehicle w/similar driving patterns who utilized long term the same octane fuel to see if there was a noticeable difference in deposits.
Another thing I've wondered is while knock sensors (460 has 4 of them) help keep things safe....I have heard this does introduce more hydrocarbons into the exhaust and CATs which could potentially shorten their lives. Just curious if this is real or a concern considering the cost of those parts these days.
Looks like down about 6 ft-lbs on torque as well from what the literature says anyway
Another thing I've wondered is while knock sensors (460 has 4 of them) help keep things safe....I have heard this does introduce more hydrocarbons into the exhaust and CATs which could potentially shorten their lives. Just curious if this is real or a concern considering the cost of those parts these days.
Looks like down about 6 ft-lbs on torque as well from what the literature says anyway
As old school as the GX is, you can still use regular in lieu of premium and it should adjust accordingly. I normally run premium but have filled up with regular when my wife forgot the GX takes premium and on a road trip when the gas station only had 87.
The butt dyno indicates that regular produces noticeably less low end power/torque so you need more throttle/rpms to make up for it. I'm sure maximum power/torque on a dyno is like 300/325 vs 290/300 but at low rpm it feels like the difference between 300 and 250.
The butt dyno indicates that regular produces noticeably less low end power/torque so you need more throttle/rpms to make up for it. I'm sure maximum power/torque on a dyno is like 300/325 vs 290/300 but at low rpm it feels like the difference between 300 and 250.
r2m
Richard
For me I've noticed lower octane to lower MPG. On a road trip a couple of years ago up to main, when we were about east of the continental divide, the octane seemed to go from 91 to ~93. When filling up with that fuel, my "butt" mpg gauge and dash were reading a couple miles per gallon higher.
I also know the few times I've used 87, my MPG has really sucked.
But as far as performance, don't really feel any difference.
I also know the few times I've used 87, my MPG has really sucked.
But as far as performance, don't really feel any difference.
Keep in mind that most 87 (at least here in the middle of the country) has 10% ethanol and ethanol has a lower energy density than normal gasoline. 91 or 93 octane premium, again at least around here, is usually ethanol free (which, as a sidebar, is why I run it in all of my small engines to avoid having ethanol ruin their fuel systems 
).
So, MPG will drop slightly when running 87, and the computer may have to up the LTFT's to accommodate it. I've been running 87 in my GX for around a year now (started was it crossed the $2/gallon threshold) and really don't tell much of a difference in power. However, I used to be able to get 19-20 mpg pretty easily, but now seem stuck in the 17-18 mpg range.
). So, MPG will drop slightly when running 87, and the computer may have to up the LTFT's to accommodate it. I've been running 87 in my GX for around a year now (started was it crossed the $2/gallon threshold) and really don't tell much of a difference in power. However, I used to be able to get 19-20 mpg pretty easily, but now seem stuck in the 17-18 mpg range.
r2m
Richard
Ah-ha!! My point exactly!
