View Poll Results: What kind of gas are you using these days?
Premium
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93
51.96%
Regular
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86
48.04%
Voters: 179. You may not vote on this poll
What kind of gas? Premium or regular? (merged GX gas threads)
#166
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if the difference is $.20 a gallon thats about $3-4 at each fill up. so if u fill up once a week on average thats about $150-250 a year difference between 87 and 91+ gasoline.
peace of mind is worth the small price each year and there is no way you can tell me that 87 is better then 91+ for any of your cars.
peace of mind is worth the small price each year and there is no way you can tell me that 87 is better then 91+ for any of your cars.
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#168
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In '05, VVT-i was added along with a bump up in compresion ratio to 10:1 and an octane requirement of 91 or better.
The Lexus New Car Features manual shows no significant changes in powertrain or the Engine management between '05-'07 GXs. Maybe the sticker was added coz people were still pumping in 87
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#169
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And the Toyota 4runner V8 had the same engine, it runs on 87 octane as well, Toyota dont even recommand 91 octane for the 4runner. Either there is some slight difference between these engines or Toyota thinks that Lexus owners can afford the higher octane gas that will increase the engine's torque slightly. Either way, the engine's computer should compensate for the lower octane. If you put in 87 and the engine doesnt knock, then it is fine.
#170
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07 4Runner New Car Features manual states 87 octane or better.
Power difference may be due to more agressive mapping in the ECU such as timing tables, which may in turn necessitate the higher octane.
Power difference may be due to more agressive mapping in the ECU such as timing tables, which may in turn necessitate the higher octane.
#171
Lexus Test Driver
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The 05 and 06 GX as well as all 4runner do not require 91 octane, the manual states 87 octane min. 91 octane recommended. They both have 10:1 compression ratio as well as the 07 and 08 GX.
Going back to the towing with 91 octane discussion earlier, it would make sense that putting in 91 octane will increase 17 ft-lb torque and would be a good idea if you are towing. The 3 horse power increase will not be notice in everyday driving. If it is the aggressive mapping of the ECU that increases the torque, then it can also retard the timing when using 87 octane with no harm to the engine. Seem to me 91 is a good idea when you are towing, but to put 91 octane in just to gain 3 horsepower in everyday driving does not make sense.
Going back to the towing with 91 octane discussion earlier, it would make sense that putting in 91 octane will increase 17 ft-lb torque and would be a good idea if you are towing. The 3 horse power increase will not be notice in everyday driving. If it is the aggressive mapping of the ECU that increases the torque, then it can also retard the timing when using 87 octane with no harm to the engine. Seem to me 91 is a good idea when you are towing, but to put 91 octane in just to gain 3 horsepower in everyday driving does not make sense.
#172
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The computer can only compensate so much. Under load such as uphill driving or heavy acceleration you may experience pinging or preignition if using lower than the recommended octane. Driving habits and conditions are also key. If you're happy with the power you have using the cheaper fuel
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#173
Lexus Test Driver
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I am referring to the 05 GX manual. You said that you are using 87, have you ever experience any pinging? I have been using both 87 and 93 octane, The only time I have notice a slight difference in accelaration is during towing otherwise, no difference in power or MPG.
#174
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Correct the equation may even be less for some people instead of more $ on a yearly basis it doesn;t always have to be higher and for those who it would be higher they shoudl get something alot more effiecient then a suv if they are concerned over saving a few hundred $'s a year but its america and we all love excess. There are numerous ways to calculate wheter its worth it or not as it pertains to other problems that may arise but not using at least what is recommended by the mfg. if u use 87 or lower then buyer beware is all i can say. there is no difference in the pre 06' engine but the 06+'s say to sue premium gas.
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funny part is most of these cars are driven by 1 person to work with no need for the 4wd or the space provided in the rear or the 7 person seating so asking us to be responsible is also a lost cause.
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funny part is most of these cars are driven by 1 person to work with no need for the 4wd or the space provided in the rear or the 7 person seating so asking us to be responsible is also a lost cause.
I have a good understanding about the formulation of higher octane fuels and the Organic chemistry associated with it. It is not the octane that causes problems within the engine, it is either impurities or lack of some detergents. The detergents are included in all brand "A" fuels, in different concentrations depending on grade. The Octane rating correlates to the speed of the fuel burn.
And as far as being a country of excess, your right, we suck. I like the ride, but I don't have to enjoy (nor am I proud of the fact) that the vehicle is a pig where fuel consumption is concerned. I didn't buy the vehicle because it uses more fuel, that would be asinine of me. Actually, I despise the fact it uses as much fuel as it does. Not just for the sake of expenditure, but do I feel a bit like a toad because it is rather environmentally unconscionable. I am not necessarily a tree hugger, but I do think at some point we will have to atone for bad behaviour.
just my 2 cents ... other opinions may vary
#175
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Sign next to the fuel cap highlights premium and manual states 91 octane recommended - -wasn't there a bump of from 235hp in 2005 to 263hp in 2006+ model year. I have the 2006 and the hp is 263hp so maybe Lexus wants us to use Premium given the changed engine hp (even though 4.7L)
#176
Lexus Test Driver
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The 2005 GX has the VVT-i engine as well and there is no premium statement on the fuel cap. The above statement may be true, Lexus want to differentiate the GX with the 4runner V8. In order to do that, they need to add horse power and torque. There were some post in the 4runner forum of people who had the 4runner V8 on a dyno with regular and premium fuel and notice a slight increase in horsepower and torque with premium.
Last edited by The G Man; 01-11-08 at 05:42 AM.
#177
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The 2005 GX has the VVT-i engine as well and there is no premium statement on the fuel cap. The above statement may be true, Lexus want to differentiate the GX with the 4runner V8. In order to do that, they need to add horse power and torque. There were some post in the 4runner forum of people who had the 4runner V8 on a dyno with regular and premium fuel and notice a slight increase in horsepower and torque with premium.
It took Lexus until the 06 model year till they realized they forgot to update the decal on the fuel door. I for one have tried both 87 and 93 octane fuel in my GX and I notice that the GX on premium fuel does respond quicker in passing situations and gets slightly better mpg. Now whether that warrants the extra 20-30 centa more a gallon, that's your decision.
#178
Lexus Test Driver
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I agree, I think all 05 and up GX and 4runners have the same engine and same ECU programming. The extra HP for the GX and being able to use regular octane gas on the 4runner is more a marketing thing for Toyota and Lexus. Both engine can run fine on 87 but they also can gain 2 or 3 horespower with premium gas. Most drivers will not notice a 2 to 3 horsepower gain in a 270 horsepower engine, but if you are towing, you will notice that 17 ft lb of torque. Gas mileage wise, I have not notice any differnce. I been going back and forth with 87 and 93 octane and try to calculate gas mileage manually for 2 years. Sometimes I get better gas mileage with regular and sometimes with 93. Over all average: 93 octane was 0.3 MPG better, but thats not a meanful number in my opinion.