SouthernSS
Owner of Southern Style Speed
- Joined
- Jul 3, 2012
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- Baton Rouge, LA
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- www.southernstylespeed.com
85 is a bit lower than recommended, but the altitude plays a part in that calculation too.
GX470 - premium fuel??
- Thread starter efog
- Start date
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I always felt that 85 at 5500ft wish worked like 87 at sea level.
NMBruce
SILVER Star
You will be hard pressed to find 87 or 93 at altitude.
Altitude plays a big roll in the ratings, since you vehicle get less air it needs less octane.
There will be no problems with lower ratings up here.
Altitude plays a big roll in the ratings, since you vehicle get less air it needs less octane.
There will be no problems with lower ratings up here.
I really just want to say that there's literally no point in not putting in premium fuel if the manufacturer recommends it. It's what the car is designed for, and the extra cost per tank is minimal. If you're going to buy a nice car, don't cheap out on it. 
The higher the octane the slower it burns. As a result, the ECU can advance timing which will create more power. Now keep in mind, the advancement or retardation of timing isn't infinite, as it's only able to advance or retard in relation to its programming. So even though your very minor lower fuel economy differences could technically be attributed to premium fuel because you're creating more power, there's many other factors that can also be attributed to those numbers. Detonation occurs when you're creating uncotrolled fuel ignition before the combustion stroke, typically as the piston is traveling downwards. A benefit of premium fuel in vehicles that either require it or don't, is it typically contains more detergents. Detergents tend to keep carbon deposits from building on valves and Pistons that are created from incomplete burning. If you have a bunch of carbon buildup, which can accumulate due to poor fuel quality among other things, pre-ignition can occur. It's different from detonation as it generally occurs as the piston is traveling upwards, when carbon deposits remain red hot from the previous combustion stroke and cause the air/fuel mixture to pre-ignite. Pre-ignition is generally much more harmful. Again, Keep in mind the truck doesn't know which of those two things is happening. It just senses abnormal cylinder noise and automatically pulls timing. Hope that makes sense, I'm watching tv as I type this.
Running a tank of mid for SnGs, no difference. Main reason I was running higher octane was for the cleaner burn. Regular with sludge up over time in our lovely motors.
Well, that's kind of a moot point since your 04 doesn't have VVTi and was designed to run on regular 87.
Same here ('03).
Last September when I rebuilt the topend of my 2000 100 series with 190k, I was amazed by how incredibly clean the engine was. The PO always used regular unleaded. Any decent quality gas now has a fair amount of detergents in it, and should not have a huge amount of buildup in a proper running engine. I also did tb,wp, and plugs on my buddies 2004 4.7 4runner with 270k on the original plugs and they still looked great. Borescope showed pretty clean pistons and that was a Midwest truck that gets crappy anything. He uses the cheapest of anything he can find. The 4.7 is an incredible motor. I drive about 3k miles a month and have used premium in a 4.7 exactly zero times. My opinion but it isn't needed unless you're towing or drag racing all the time.
If you regularly run 87, you won't have the stepped performance, or knocking (shouldn't, anyway). The long term adaptives have adjusted the timing lower, so you should be running smooth - but at a cost of less timing, which equates to less power. But if you aren't Autocrossing your GX, you'd probably not notice the difference.....
I run 93 tier 1 gasoline in my V8 4R. There is a CLEAR difference in performance and MPG. It's worth the marginal increase in cost.
260 vs 263 for a 06 4Runner vs GX470. 3 hp. You would have a hard time justifying that there is even a difference as engine to engine differences are probably larger then that.
NMBruce
SILVER Star
gotta agree
This is from toyota120.com for a 2006 model
4Runner = V8 260HP @ 5400 RPM and 306lb-ft @ 3400 RPM
Lexus GX470 = 263 HP at 5400 RPM and 323 lb-ft at 3400 RPM.
271hp and 313tq for the 06 Tundra that runs on Reg Fuel.
The interesting thing is that the GX does have a decent amount more tq. It is very possible that the TQ increase is due to a Timing bump at that RPM band. So maybe there is something different. I don't know. It's a mess. My 06 Tundra was a TQ'less dog IMHO. Only thing I didn't like about that truck.
NMBruce
SILVER Star
looks like compress ratio is the same for the GX470 & 4Runner at 9.6-1
So could it be the head, intake or the exhaust
So could it be the head, intake or the exhaust
Seriously doubt this.
Mechanically they're IDENTICAL. It's ECU tuning aggressiveness. Trust me, drive with premium, you will notice the difference.
I have tried to find it but there was a document with posted dyno results for the 2UZ with different fuel direct from Toyota.
NMBruce
SILVER Star
I don't notice the difference
regular gas here no problem. Runs like a champ.
Than you're not as observant as I am.
NMBruce
SILVER Star
Maybe, maybe not
I'll just leave it as with this you see the difference and I don't, nothing more or less.
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