View Poll Results: What kind of gas do you use?
91
546
41.65%
92
68
5.19%
93
612
46.68%
I'll put anything in there CHEAP!
85
6.48%
Voters: 1311. You may not vote on this poll
The mother of all 2IS gas discussions. Premium or Mid-grade (merged threads)
12-02-05, 07:35 PM
#32
Lexus Connoisseur
Originally Posted by 4DOORFUN
Whether or not an engine is considered "hi-tech" as nothing to do with it's tolerance for pinging. Pinging is simply more likely to occur in engines with high compression ratios, high engine cylinder temps., and advanced timing. Yes, the IS350 has a twin cam set-up with direct injection. Great, but that has nothing to do with pinging.
My 2000 Mustang GT 2V 4.6L SOHC V8 engine is hardly considered "high tech". However, ever since I increased engine timing and leaned out the a/f ratio, I need to be concerned with pinging. I now run 91 octane fuel. It's still the same old "low tech" engine, but now it's pushed to the limits for the stock fuel system. I was able to grab peak gains of 8 rwhp/10 rwtq. from the tune. Those are not large gains, but my point is there is always something extra left over. The IS350 is no different. BTW, I tuned my car while performing wide open throttle runs on a dyno. It's the only way to do it properly.
If we were talking about a limited production car like a Viper or ZO6, I'd be more willing to bet those car are maxed out from the factory tune.
BTW, I realize the IS350 doesn't have a distributor. Are you kidding me with that?
My 2000 Mustang GT 2V 4.6L SOHC V8 engine is hardly considered "high tech". However, ever since I increased engine timing and leaned out the a/f ratio, I need to be concerned with pinging. I now run 91 octane fuel. It's still the same old "low tech" engine, but now it's pushed to the limits for the stock fuel system. I was able to grab peak gains of 8 rwhp/10 rwtq. from the tune. Those are not large gains, but my point is there is always something extra left over. The IS350 is no different. BTW, I tuned my car while performing wide open throttle runs on a dyno. It's the only way to do it properly.
If we were talking about a limited production car like a Viper or ZO6, I'd be more willing to bet those car are maxed out from the factory tune.
BTW, I realize the IS350 doesn't have a distributor. Are you kidding me with that?
Most people don't realize modern Toyota/Lexus engines use Toyota Direct Ignition systems (TDI) which is why it was mentioned.
12-03-05, 01:34 PM
#33
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Originally Posted by flipside909
The point i'm trying to make is Toyota/Lexus already maximizes output of these engines and able to keep them with low emission levels and have outstanding fuel economy. How is the IS350 no different? Tell me how to increase engine timing and leaning out the a/f ratio without having to use a piggyback computer (S-AFC) or modify the stock ECU (good luck with that). Out of curiousity would you risk leaning out the a/f ratio on a 11.8:1 c/r of the 3.5L 2GR-FSE or the 12:1 c/r of the 2.5L 4GR-FSE? Knock sensors on Toyota V6s are not cheap to replace. Better yet, have you ever worked on a Toyota/Lexus engine and made the same gains with the tweaks you mentioned above?
Most people don't realize modern Toyota/Lexus engines use Toyota Direct Ignition systems (TDI) which is why it was mentioned.
Most people don't realize modern Toyota/Lexus engines use Toyota Direct Ignition systems (TDI) which is why it was mentioned.
I'll agree to disagree with you.
12-03-05, 04:09 PM
#34
Lexus Connoisseur
Originally Posted by 4DOORFUN
No mass produced car is maxed out from the factory. There is room for more power on the IS, but you may not meet emissions after tweaking the car. There are ways around that too.
I'll agree to disagree with you.
I'll agree to disagree with you.
12-06-05, 06:21 AM
#36
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I'm very new to lexus, I test drove a gs300 and is250 awd, I'm considering the is because as much as I want extra leg room in the back, I'll hardly every occupy that seat, but the dealership salesman was telling me both gs and is only take regular gas..........I sold my bmw, so I was kind of weary of his statement......from what everyone states here......I'm assuming he didn't read the fine print
12-06-05, 01:56 PM
#37
Originally Posted by krs71
I'm very new to lexus, I test drove a gs300 and is250 awd, I'm considering the is because as much as I want extra leg room in the back, I'll hardly every occupy that seat, but the dealership salesman was telling me both gs and is only take regular gas..........I sold my bmw, so I was kind of weary of his statement......from what everyone states here......I'm assuming he didn't read the fine print
12-06-05, 02:27 PM
#38
Lexus Test Driver
Listen to Flipside on this one folks....
On pages 384-5 in the owner's manual it goes into the gas requirements.
IS250: The use of such gasoline will cause persistent knocking. If severe this will lead to engine damage.
IS350: The use of such gasoline may cause the engine to knock or drastically reduce output to protect itself while driving with a heavy load. To avoid this refill the tank with Premium unleaded gasoline as soon as possible.
Don't make assumptions based on previous experiences. These are new engine designs and not related to other generations of Lexus in their fuel requirements.
Rock
IS250: The use of such gasoline will cause persistent knocking. If severe this will lead to engine damage.
IS350: The use of such gasoline may cause the engine to knock or drastically reduce output to protect itself while driving with a heavy load. To avoid this refill the tank with Premium unleaded gasoline as soon as possible.
Don't make assumptions based on previous experiences. These are new engine designs and not related to other generations of Lexus in their fuel requirements.
Rock
12-06-05, 09:58 PM
#39
Lexus Connoisseur
Thanks Rock! :approve:
12-27-05, 02:33 PM
#40
Lexus Test Driver
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You know.......I was thinking about this a little.....sorry to drag it back to the top.......
Premium vs. med grade vs standard grade gas all costs the same to produce.........why then do we as consumers pay more for it at the pump? if a green apple costs 10 cents to grow, and so does a red apple, does it really make sense to buy the red apple for 15 cents when I could have the same thing for less? They are both just apples........
Premium vs. med grade vs standard grade gas all costs the same to produce.........why then do we as consumers pay more for it at the pump? if a green apple costs 10 cents to grow, and so does a red apple, does it really make sense to buy the red apple for 15 cents when I could have the same thing for less? They are both just apples........
12-27-05, 03:07 PM
#41
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I dont honestly see the point of argument here. You've paid 40K for the car and it's only 3$ difference if you filled up your tank with premium rather than regular. So if you filled up twice a week, that's 24$ and about 300$ a year. I rather pay 300$ more for a year than listening to the poor engine knocking noise. 
12-27-05, 04:30 PM
#43
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this is an age-old debate ever since premium gasoline became available. All modern engines can alter the control system to avoid knocking. Notice Lexus states that it can cause knocking and decreased performance "under heavy load" condition. Whether one should absolutely use premium gasoline depends on your driving condition. Most people don't keep their cars long enough to see the damage, if there's any--same way most people don't see the longterm benefits of synthetic oil (the part about decreased engine wear). That being said, I still use premium because you don't really save all that much, compared to the total cost of owning the vehicle, by switching to regular. Just go with the manufacturer's advice.
12-27-05, 04:40 PM
#44
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On the fuel stations that only have the one hose for fueling of all 3 grades of fuel, does any one know the amount of say 87 octane fuel gets left in the hose before the 93 octane fuel starts to come out the nozzle? Just wondering.
12-27-05, 06:20 PM
#45
Lexus Champion
Such hypocracy here. You fill your tank with regular unleaded because it doesn't matter yet if you go to purchase a used car from a stranger and he says he's put regular unleaded in it since day one (tank says premium unleaded only), you balk. 