Fuel discussions/questions - Octane Regular or Premium (merged threads)
08-31-17, 10:48 AM
#166
I live in Massachusetts and cannot find 91. We have 87, 89, and 93. I have been using 93 for the last 3 months since I bought my GX, but lately and moving forward will fill with 1/2 tank of 89 and 1/2 a tank of 93, to self-blend to the required 91. Saves me a few bucks!
08-31-17, 11:14 AM
#167
Tundra 4.6 is 310HP @ 5600 RPM / 327 lb-ft @ 3400 RPM
GX is 301 HP @ 5500 RPM / 329 lb-ft @ 3500 RPM
Compression Ratio is 10.2:1 in both applications
Not sure if it is true anymore but at one time there were more detergents in Premium fuel. I've always tried to use Premium in the vehicles that recommended or required it as I've felt a performance penalty when lower grades were used.
GX is 301 HP @ 5500 RPM / 329 lb-ft @ 3500 RPM
Compression Ratio is 10.2:1 in both applications
Not sure if it is true anymore but at one time there were more detergents in Premium fuel. I've always tried to use Premium in the vehicles that recommended or required it as I've felt a performance penalty when lower grades were used.
FWIT, I've been a major gearhead for nearly 50 years. I've read a tremendous amount, owned MANY high performance boats, cars, and motorcycles and have some amateur racing experience. I don't claim to be an expert, but I trust what I have learned. If I lived in an area with a lot of hills that puts a greater load on an engine, or if the vehicle was driven hard a lot (it's my wifes) I would probably err towards the need for a higher octane. But neither of those conditions exist for me.
Last edited by jjscsix; 08-31-17 at 11:20 AM.
08-31-17, 11:25 AM
#168
I was a skeptic too until I heard about, and investigated the two engines.
08-31-17, 12:54 PM
#169
Lexus Fanatic
When you shampoo your hair do you shampoo, rinse and repeat just because the label says so? Do you really think there is no chance that they are just just being over protective? Do you really think there is some difference between the Toyota version and the Lexus version that changes the octane need? I don't.
I was a skeptic too until I heard about, and investigated the two engines.
I was a skeptic too until I heard about, and investigated the two engines.
Why would Lexus pretend you need 91 octane but in fact it is really not needed?
This is the answer direct from Lexus. http://lexus2.custhelp.com/app/answe...dCRnlybg%3D%3D
Last edited by Toys4RJill; 08-31-17 at 12:57 PM.
08-31-17, 01:43 PM
#170
If you want peak results, then why wouldn't you want to shampoo, rinse then repeat. Or in the case of the GX460 use the required premium fuel.
Why would Lexus pretend you need 91 octane but in fact it is really not needed?
This is the answer direct from Lexus. http://lexus2.custhelp.com/app/answe...dCRnlybg%3D%3D
Why would Lexus pretend you need 91 octane but in fact it is really not needed?
This is the answer direct from Lexus. http://lexus2.custhelp.com/app/answe...dCRnlybg%3D%3D
I ran 87 and 89 on my 2010 RX350 for 42k miles (unitl I sold it) with NO PROBLEMS.
I have run 89 (sometimes 91) on my '15 GX with no issues at all (about 25k miles now). We also had four 4Runners ('02, '03 V8, '04 V6, and '05 V8) and NEVER put premium in them. We still have 1 with about 80k miles and it is fine.
YES, low fuel grade does effect MPG (at least in my experience and I manually calculate MPG every fill ups)
08-31-17, 02:08 PM
#171
Lexus Champion
If a driver can't feel the difference when different fuel is pumped, what is the bother? Manual is written by engineers who design the vehicle. (I am a retired PE but not
mechanical engineer). To me higher Octane fuel seem to have more beneficial additives. There is a limit what ECU can do. I always follow what owner's manual says.
It also matters what terrain you are mostly driving. Sea level has higher density air. I live in the Rockies my home is at 1000 ft. above sea level. My cabin is at about 4000 ft above sea level. I often drive up logging road as high as 6000 ft above seal level. Would I mess with fuel grade?, NO!
mechanical engineer). To me higher Octane fuel seem to have more beneficial additives. There is a limit what ECU can do. I always follow what owner's manual says.
It also matters what terrain you are mostly driving. Sea level has higher density air. I live in the Rockies my home is at 1000 ft. above sea level. My cabin is at about 4000 ft above sea level. I often drive up logging road as high as 6000 ft above seal level. Would I mess with fuel grade?, NO!
08-31-17, 02:23 PM
#172
Lexus Fanatic
If you look at the fine print, the 2011 rating of 275hp is rated using premium 91 during testing, while the 2012 is rated at 270HP using regular 87. SAE specs require this.
09-01-17, 07:54 AM
#173
I KNOW this by heart. The point is you MIGHT loose few HPs but it will NOT hurt your engine, period. I also doubt that anyone can tell the different between 270 vs. 275 hp.
09-01-17, 08:06 AM
#174
Lexus Fanatic
But you don't know that the engine might not be hurt. Nobody has been able to answer this:. Why would Lexus lie to everyone and say that if you don't use premium fuel, then engine damage could occur?
09-01-17, 08:09 AM
#175
Most places, Regular = 87 Octane Mid-Grade = 89 Octane Premium = 91 Octane
I found a Circle K Gas station that sells Premium = 93 Octane for about $0.15 less than the Shell across the street who sells Premium = 91 Octane... $2.72 vs $2.89 and higher octane = a DOUBLE WIN!!!!
I found a Circle K Gas station that sells Premium = 93 Octane for about $0.15 less than the Shell across the street who sells Premium = 91 Octane... $2.72 vs $2.89 and higher octane = a DOUBLE WIN!!!!
09-01-17, 08:14 AM
#176
Most places, Regular = 87 Octane Mid-Grade = 89 Octane Premium = 91 Octane
I found a Circle K Gas station that sells Premium = 93 Octane for about $0.15 less than the Shell across the street who sells Premium = 91 Octane... $2.72 vs $2.89 and higher octane = a DOUBLE WIN!!!!
I found a Circle K Gas station that sells Premium = 93 Octane for about $0.15 less than the Shell across the street who sells Premium = 91 Octane... $2.72 vs $2.89 and higher octane = a DOUBLE WIN!!!!
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09-01-17, 09:12 AM
#177
It's not that Lexus is lying, it's that higher octane gets slightly better fuel economy and they have to meet government CAFE standards across their fleet. So they say "premium only" and can lock in the fuel economy numbers using premium gas and pad it a bit. It also gets slightly better performance, something many Lexus drivers are willing to pay for. I'm sure this same engine sold in other parts of the world doesn't have this requirement and does fine on lower octane.
I'm not advocating running regular unleaded, but I have seen zero evidence it has ever caused damage on newer vehicles. On my last GX, I started running 87 octane for several years and had no problems. It also said "premium only".
On older cars that didn't have knock sensors, you could have real engine damage with the wrong octane because the timing was not adjusted by a computer on the fly. Cars though have had knock sensors that can adjust the timing to the octane for at least 20+ years.
09-01-17, 09:44 AM
#178
Lead Lap
While I agree that the best advice in these matters is to use the required or recommended octane in the manual. I think the idea here is, Lexus does not want to falsely advertise their specs, as doing so would open them up to litigation. Ie Lexus advertises the GX can make 301 hp then states premium is not required. Somebody dynos the car on 87, finds out they hp numbers nowhere near that, decides to sue. Outlandish but happens. Toyomoco being a risk adverse company after all right
09-01-17, 09:47 AM
#179
Lexus Champion
Are you an automotive engineer? If your engine developed a problem and needs major work under warranty, The dealer service manager says, 'you've been running lower Octane fuel with your car which caused this problems. Warranty is void' Do you have an authority to counter that?
You can hire a lawyer but Lexus can have more lawyers than you can hire.
09-01-17, 09:51 AM
#180
Lexus Fanatic
It's not that Lexus is lying, it's that higher octane gets slightly better fuel economy and they have to meet government CAFE standards across their fleet. So they say "premium only" and can lock in the fuel economy numbers using premium gas and pad it a bit. It also gets slightly better performance, something many Lexus drivers are willing to pay for. I'm sure this same engine sold in other parts of the world doesn't have this requirement and does fine on lower octane.
I'm not advocating running regular unleaded, but I have seen zero evidence it has ever caused damage on newer vehicles. On my last GX, I started running 87 octane for several years and had no problems. It also said "premium only".
On older cars that didn't have knock sensors, you could have real engine damage with the wrong octane because the timing was not adjusted by a computer on the fly. Cars though have had knock sensors that can adjust the timing to the octane for at least 20+ years.
I'm not advocating running regular unleaded, but I have seen zero evidence it has ever caused damage on newer vehicles. On my last GX, I started running 87 octane for several years and had no problems. It also said "premium only".
On older cars that didn't have knock sensors, you could have real engine damage with the wrong octane because the timing was not adjusted by a computer on the fly. Cars though have had knock sensors that can adjust the timing to the octane for at least 20+ years.