Side effects of regular gas?
03-09-16, 04:18 PM
#1
Pit Crew
Thread Starter
Side effects of regular gas?
Sorry if the thread's been made, but I let my father borrow my car and he said he topped up the tank (it was either half full or 1/4 full) with regular. What can I expect from this, just bad mileage?
03-09-16, 06:07 PM
#2
Don't think twice about it, just don't do it very often.
I've put regular in my car once because it was the middle of nowhere and the station only had regular. Nothing bad happened except slightly worse gas mileage. I just wouldn't do it unless theres no choice or it happened on accident.
I've put regular in my car once because it was the middle of nowhere and the station only had regular. Nothing bad happened except slightly worse gas mileage. I just wouldn't do it unless theres no choice or it happened on accident.
As to side effects, I wouldn't know because I always use what the vehicle is made to burn.
03-09-16, 07:15 PM
#5
Pit Crew
Thread Starter
Alright, thanks. Also, just a hypothetical, what if you used 87 for like a year? I swear this isn't me lmao i'm not stupid, just argued with my dad about its importance and i wanna clear it up.
03-09-16, 11:20 PM
#7
The 2JZ-GE was designed to run premium fuel. Usually that's 91, 92 or 93. You can run lower octane for short periods if that's all that's available or 90 octane at high elevation but outside of those unique circumstances you should be using premium fuel only. Your ECU will compensate by pulling ignition timing but it's not intended as a long term countermeasure to detonation. That's what the premium fuel is for.
Just how it was designed. Remember how cheap premium fuel was in 1992 when these things first came out. And who was buying them new. Also, that the JZ engine isn't your average Camry V6.
Just how it was designed. Remember how cheap premium fuel was in 1992 when these things first came out. And who was buying them new. Also, that the JZ engine isn't your average Camry V6.
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03-10-16, 05:57 AM
#8
Keeper of the light
iTrader: (17)
I won't waste the money on anything over 10 years old, unless its 50 years old. When the car was new…... before half it's owners could walk, and the engine management systems were in top shape, The car was running clean enough to see a loss. Anything with that many years and miles is already running at compensated amount within the percentage the ecu would adjust just to get past the gunk in the heads, lines, and tank. The problem with looking at things on paper is…… nobody ever has all the paper. The real world variables apply.
03-10-16, 02:42 PM
#9
How does that change the fact that the SC's engine and engine management system were designed to run on premium fuel?
Some fifty year old cars with less than top-spec engines weren't even designed to require premium fuel. The only thing they're missing is lead in the gas to lubricate valve seats unless the fifty year old engine has been rebuilt or replaced with a newer or redesigned powerplant by now.
Some fifty year old cars with less than top-spec engines weren't even designed to require premium fuel. The only thing they're missing is lead in the gas to lubricate valve seats unless the fifty year old engine has been rebuilt or replaced with a newer or redesigned powerplant by now.
03-10-16, 03:04 PM
#10
regular gas = regular performance. won't hurt a thing.
its a worthy mention that fuel has improved since the SC has been out. that 10% e85 helps suppress knock.
I used to run mid grade on my non turbo cars, and premium on the turbo cars (always). since gas is cheap now I run premium on all the cars. lots of people run the low grade and it wont hurt anything, but you will loose a little performance if the ecu scales back the timing a hair, its really not a big deal if you don't have a turbo strapped to it.
Lexus just likes to put that sticker on the car (its part of the classy car feel), like the 2uz in a LX470 says premium only, same as my gx470, but the 2uz in a landcruiser 100 series or 4th gen 4runners do not say that. I would think most 4runners are running around on regular. If you really think the lexus version has a tune that makes that much more power and cannot handle regular gas like the other ones, then you may want to reconsider. will regular make your engine run as buttery smooth and as powerful as premium, probably not but it will get you down the street just fine.
its a worthy mention that fuel has improved since the SC has been out. that 10% e85 helps suppress knock.
I used to run mid grade on my non turbo cars, and premium on the turbo cars (always). since gas is cheap now I run premium on all the cars. lots of people run the low grade and it wont hurt anything, but you will loose a little performance if the ecu scales back the timing a hair, its really not a big deal if you don't have a turbo strapped to it.
Lexus just likes to put that sticker on the car (its part of the classy car feel), like the 2uz in a LX470 says premium only, same as my gx470, but the 2uz in a landcruiser 100 series or 4th gen 4runners do not say that. I would think most 4runners are running around on regular. If you really think the lexus version has a tune that makes that much more power and cannot handle regular gas like the other ones, then you may want to reconsider. will regular make your engine run as buttery smooth and as powerful as premium, probably not but it will get you down the street just fine.
Last edited by Ali SC3; 03-10-16 at 03:11 PM.
03-10-16, 04:05 PM
#11
I stand corrected then : / And I just learned something about modern fuel knock resistance.
There's a pretty big difference between the 91 in CA and the 93 that most of the country gets anyway. Plus the 90 that is the highest some areas get. So would this suggest that both 89 *and* 87 are technically okay? Or just the mid-grade 89?
There's a pretty big difference between the 91 in CA and the 93 that most of the country gets anyway. Plus the 90 that is the highest some areas get. So would this suggest that both 89 *and* 87 are technically okay? Or just the mid-grade 89?
03-11-16, 09:29 AM
#13
normally areas have 89, 91 and 93. at higher elevation there is less air so we have 87, 89 and 91 in Denver its pretty much the same as using those other ones at sea level. I run 91 here and am pushing at least 16-18 psi everytime I drive the car without issues (With tt headgasket), same with my brothers BPU tt supra around the same psi, so its not like 91 is terrible or anything but if there was 93 we would be filling that up on a turbo car. alot of people switch to e85 here after a certain power point to not worry about it anymore.
I want to say my pops runs only 87 in his v8 4runner and regular dino oil (he is of the oldschool), I can never seem to tell the difference between how his runs and how my gx runs with the same engine but with premium gas and fully synthetic oil in it. maybe there is a hair less acceleration on his, but at the end of the day they both run smooth and well and both get terrible gas mileage, so those who say you can run regular know what they are talking about, toyota/lexus are designed to be able to run regular or even worse gas than regular, they just scale back the performance some. if you put premium you will get the full tune and a little more performance, which may or may not be worth it to your wallet. If you aren't flooring the pedal all the time and generally drive pretty slowly, you might as well be using regular.
california.... well they sort of just invent their own problems, they have 91 at sea level and as you suspect its isn't as good as 93, but it will get the job done for bpu boost levels still. This probably has helped make switching to E85 popular, its emissions friendly and all the knock resistance you can get until the day you push the tune too far and the motor flies apart (there isn't knock to warn you), but most good tuners know not to do that.
I want to say my pops runs only 87 in his v8 4runner and regular dino oil (he is of the oldschool), I can never seem to tell the difference between how his runs and how my gx runs with the same engine but with premium gas and fully synthetic oil in it. maybe there is a hair less acceleration on his, but at the end of the day they both run smooth and well and both get terrible gas mileage, so those who say you can run regular know what they are talking about, toyota/lexus are designed to be able to run regular or even worse gas than regular, they just scale back the performance some. if you put premium you will get the full tune and a little more performance, which may or may not be worth it to your wallet. If you aren't flooring the pedal all the time and generally drive pretty slowly, you might as well be using regular.
california.... well they sort of just invent their own problems, they have 91 at sea level and as you suspect its isn't as good as 93, but it will get the job done for bpu boost levels still. This probably has helped make switching to E85 popular, its emissions friendly and all the knock resistance you can get until the day you push the tune too far and the motor flies apart (there isn't knock to warn you), but most good tuners know not to do that.
03-25-16, 10:11 AM
#14
Ali's comments compelled me to give Regular a try on my last fill-up, just to see if I could notice a difference. Worst case scenario, it sounds like, is a bit of reduced performance and a tank or two to flush the lower octane through and reset the ECU. (Or just pull the EFI fuse when the tank is used up.) It only took a little over a third of a tank to fill up, so I probably just averaged the octanes out to 89-90, assuming they mix that way, but so far I haven't noticed anything.
A couple days ago, I ran across this article:
https://grassrootsmotorsports.com/articles/fuel-truth/
Of note: "The 87 octane gas required that we pull the ignition timing back 1 degree and dial back the fuel 2 percent. The result was 1 less horsepower and a solid 7-lb.-ft. loss in torque. TAKE-HOME MESSAGE: Don’t cheap out—go for the good stuff if you’re tuned for it."
That's on a car that doesn't call for Premium in stock form, so I would think our tunes are losing power with Regular. Maybe the 4Runner vs SC's fueling difference is in the ECU, not the engine?
A couple days ago, I ran across this article:
https://grassrootsmotorsports.com/articles/fuel-truth/
Of note: "The 87 octane gas required that we pull the ignition timing back 1 degree and dial back the fuel 2 percent. The result was 1 less horsepower and a solid 7-lb.-ft. loss in torque. TAKE-HOME MESSAGE: Don’t cheap out—go for the good stuff if you’re tuned for it."
That's on a car that doesn't call for Premium in stock form, so I would think our tunes are losing power with Regular. Maybe the 4Runner vs SC's fueling difference is in the ECU, not the engine?
03-25-16, 10:23 AM
#15
you see the difference on that test is that they used a standalone, so it doesn't matter what the car "called for" cause that is only with regards to the stock ecu and stock tune (known to be conservative power wise).
so they had it "tuned up" for the premium fuel, so there is more of a difference when running regular where they had to "tune it back down".. and still they only lost 1hp and 7 ft/lbs, most people would not even notice that.
This is the loosing a hiar of performance I was referring to, you will loose some power obviously, but its not enough that most people would notice from day to day.
My take on it is, the factory ecu is not really extra "tuned up" for premium as they are tuned pretty conservative timing wise from the factory, remember the same ecu has to power thousands of engines with thousands of small different variances, they are not able to tune timing to the edge of knock and back it off 2 degrees like you would on a standalone, they have to tune it more conservatively so that even a worn engine low on compression or a brand new engine will both still run without knock at WOT (really the sticker is mainly there to make you feel better about emptying your wallet for that luxury car), so ultimately you wont even loose as much power when using a factory ecu because the ecu is already conservatively tuned for premium and can tolerate regular without pulling much timing at all.
what power you do loose will be minimal, the car will not self destruct and generally speaking if your relative filled it with regular and did not tell you, I doubt you would really notice unless you are very in tune with your car.
The take away is, running regular wont hurt anything, but if you want to squeeze out every last bit of performance no matter how small that may be... then for sure run premium all the time, it does help a little bit but raising the octane past a certain point on the stock ecu wont do anything cause the stock ecu will not advance timing.
What some people used to do is advance the distributor a few degrees and run premium all the time, and you can notice a bit of extra performance there, but that will only work on the 2jz-ge with an adjustable distributor, and you will get points where the motor may knock and the ecu will dial those points back, but often it will learn to settle the timing around where it was stock and put you back at square one unless you keep resetting the ecu.
so they had it "tuned up" for the premium fuel, so there is more of a difference when running regular where they had to "tune it back down".. and still they only lost 1hp and 7 ft/lbs, most people would not even notice that.
This is the loosing a hiar of performance I was referring to, you will loose some power obviously, but its not enough that most people would notice from day to day.
My take on it is, the factory ecu is not really extra "tuned up" for premium as they are tuned pretty conservative timing wise from the factory, remember the same ecu has to power thousands of engines with thousands of small different variances, they are not able to tune timing to the edge of knock and back it off 2 degrees like you would on a standalone, they have to tune it more conservatively so that even a worn engine low on compression or a brand new engine will both still run without knock at WOT (really the sticker is mainly there to make you feel better about emptying your wallet for that luxury car), so ultimately you wont even loose as much power when using a factory ecu because the ecu is already conservatively tuned for premium and can tolerate regular without pulling much timing at all.
what power you do loose will be minimal, the car will not self destruct and generally speaking if your relative filled it with regular and did not tell you, I doubt you would really notice unless you are very in tune with your car.
The take away is, running regular wont hurt anything, but if you want to squeeze out every last bit of performance no matter how small that may be... then for sure run premium all the time, it does help a little bit but raising the octane past a certain point on the stock ecu wont do anything cause the stock ecu will not advance timing.
What some people used to do is advance the distributor a few degrees and run premium all the time, and you can notice a bit of extra performance there, but that will only work on the 2jz-ge with an adjustable distributor, and you will get points where the motor may knock and the ecu will dial those points back, but often it will learn to settle the timing around where it was stock and put you back at square one unless you keep resetting the ecu.
Last edited by Ali SC3; 03-25-16 at 10:35 AM.