Ownership Experience - 200t Premium vs Regular Fuel
08-22-15, 05:31 AM
#106
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I've filled up with 87 and 93 and I have noticed that with 87 octane the yellow overcast mode cuts off much sooner, but otherwise there is no difference. With the exception of exotics, all other cars that require 91 or 93 can safely use 87 as well as the engine management system will adjust timing or boost levels to avoid any possible damage. Most system can adjust the timing each revolution for each cylinder, so they respond very quickly. The requirements are also to keep the engine running optimally under the most difficult conditions, such as 110° days, fully loaded, going up hills etc.
Ive; dynode two cars using different fuels.
2008 VW R32, required 91 octane. Normally aspirated 3.2L V6 rated at 265 hp put about 230hp to the wheels and it did not matter using 87 octane E10, 93 octane E10 or 90 octane E0 fuel.
2012 Subaru WRX, 2.5L turbo H4 rated at 265 HP. Delivered 289 HP to the wheels with 93 octane and 240 with 87 octane. So the ECU certainly cut back boost and timing
Ive; dynode two cars using different fuels.
2008 VW R32, required 91 octane. Normally aspirated 3.2L V6 rated at 265 hp put about 230hp to the wheels and it did not matter using 87 octane E10, 93 octane E10 or 90 octane E0 fuel.
2012 Subaru WRX, 2.5L turbo H4 rated at 265 HP. Delivered 289 HP to the wheels with 93 octane and 240 with 87 octane. So the ECU certainly cut back boost and timing
08-24-15, 09:43 AM
#107
Lexus Test Driver
With the exception of exotics, all other cars that require 91 or 93 can safely use 87 as well as the engine management system will adjust timing or boost levels to avoid any possible damage. Most system can adjust the timing each revolution for each cylinder, so they respond very quickly. .
2008 VW R32, required 91 octane. Normally aspirated 3.2L V6 rated at 265 hp put about 230hp to the wheels and it did not matter using 87 octane E10, 93 octane E10 or 90 octane E0 fuel.
2012 Subaru WRX, 2.5L turbo H4 rated at 265 HP. Delivered 289 HP to the wheels with 93 octane and 240 with 87 octane. So the ECU certainly cut back boost and timing
2008 VW R32, required 91 octane. Normally aspirated 3.2L V6 rated at 265 hp put about 230hp to the wheels and it did not matter using 87 octane E10, 93 octane E10 or 90 octane E0 fuel.
2012 Subaru WRX, 2.5L turbo H4 rated at 265 HP. Delivered 289 HP to the wheels with 93 octane and 240 with 87 octane. So the ECU certainly cut back boost and timing
08-24-15, 11:05 AM
#108
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I think just about every car from main stream brands will be able to adapt to lower then idea octane. Not worth the risk to damage an engine from someone who puts in the wrong fuel.
03-18-18, 08:21 AM
#109
Reviving old thread, I know but:
According to Doug Herbert at Lexus, “Required” is a bit overstated.Herbert said that both vehicles (an RC 350 sports coupe and an NX 200t compact SUV) will run on regular-grade fuel without damage. But since both the advertised power ratings and the EPA fuel-economy figures were attained using premium, that’s what they have to put as the required fuel. However, he also warned that continued use of regular-grade gas would cause the engine’s computer to back off on the ignition timing—thus adversely affecting both power and fuel economy—and that it would continue to do so for a time even after the car is filled with premium.It’s important to note that Herbert’s advice only applies to Lexus vehicles, as he obviously can’t speak for other manufacturers—and we can’t, either. And while our stance is that you should use premium-grade fuel if it’s stated to be “Required” or “Only,” here are some thoughts if you accidentally fill it with regular.Detonation is your concern, and as it mostly occurs under hard acceleration, tread lightly on the throttle. Listen carefully for the telltale knock or ping that indicates detonation, which means you should try and keep other noises (such as the radio or conversation) to a minimum so you can hear it. As soon as you get down to a quarter or half a tank, fill it with premium, which will raise the average octane level fed to the engine. This cp is from Consumer report article and from Lexus USA rep. I figure, this should be the final answer. Yes, you can run 87 if you were to drive gently. I don't think there's anything else to discuss here, as the final word came from Lexus itself, so much bowed toin this thread.
According to Doug Herbert at Lexus, “Required” is a bit overstated.Herbert said that both vehicles (an RC 350 sports coupe and an NX 200t compact SUV) will run on regular-grade fuel without damage. But since both the advertised power ratings and the EPA fuel-economy figures were attained using premium, that’s what they have to put as the required fuel. However, he also warned that continued use of regular-grade gas would cause the engine’s computer to back off on the ignition timing—thus adversely affecting both power and fuel economy—and that it would continue to do so for a time even after the car is filled with premium.It’s important to note that Herbert’s advice only applies to Lexus vehicles, as he obviously can’t speak for other manufacturers—and we can’t, either. And while our stance is that you should use premium-grade fuel if it’s stated to be “Required” or “Only,” here are some thoughts if you accidentally fill it with regular.Detonation is your concern, and as it mostly occurs under hard acceleration, tread lightly on the throttle. Listen carefully for the telltale knock or ping that indicates detonation, which means you should try and keep other noises (such as the radio or conversation) to a minimum so you can hear it. As soon as you get down to a quarter or half a tank, fill it with premium, which will raise the average octane level fed to the engine. This cp is from Consumer report article and from Lexus USA rep. I figure, this should be the final answer. Yes, you can run 87 if you were to drive gently. I don't think there's anything else to discuss here, as the final word came from Lexus itself, so much bowed toin this thread.
04-23-18, 11:24 AM
#117
Lexus Champion
my salesman actually said i could get away with the mid grade fuel. but when i saw the sticker on the fuel door stating premium fuel only..that was more than enough to convince me.
04-23-18, 12:03 PM
#119
Lead Lap
I'll be the contrarian here.
Government regulations require auto manufacturers to recommend the use of the same grade of fuel that they use in EPA testing for fuel economy, horsepower rating, and emissions testing. Lexus has chosen to use premium fuel for such testing because use of premium fuel results in a marginally higher horsepower rating, marginally better fuel economy, and an ultra low emissions vehicle rating. Thus, Lexus is required to recommend the use of premium fuel. The reality, however, is that most modern cars, especially ones with relatively low compression ratios will perform without problems and with minimal loss of horsepower or fuel economy with regular grade fuel. With a compression ratio of 10:1, the NX fits into that category. Further, you will find that the gas pumps at most Lexus dealers only have regular fuel, and that is what they put in the vehicles on their lot, in their loaners, etc.
If the price of premium fuel was $.10-.15 higher than that of regular grade fuel, it would be easier to make the case for using premium grade fuel, but, in the last few years, the price gap between regular fuel and premium fuel in most areas has risen to $.50 or more per gallon. With the cost of premium fuel being $.50 or more higher than the price of regular fuel, the extra cost of using premium fuel is not insignificant. For a typical driver, using premium fuel over a 5 year period of ownership would add up to over $2500 in extra cost over using regular fuel, and the benefits in horsepower would be, to most, unnoticeable, while the improvements in fuel economy would not be close enough to justify the extra cost.
Government regulations require auto manufacturers to recommend the use of the same grade of fuel that they use in EPA testing for fuel economy, horsepower rating, and emissions testing. Lexus has chosen to use premium fuel for such testing because use of premium fuel results in a marginally higher horsepower rating, marginally better fuel economy, and an ultra low emissions vehicle rating. Thus, Lexus is required to recommend the use of premium fuel. The reality, however, is that most modern cars, especially ones with relatively low compression ratios will perform without problems and with minimal loss of horsepower or fuel economy with regular grade fuel. With a compression ratio of 10:1, the NX fits into that category. Further, you will find that the gas pumps at most Lexus dealers only have regular fuel, and that is what they put in the vehicles on their lot, in their loaners, etc.
If the price of premium fuel was $.10-.15 higher than that of regular grade fuel, it would be easier to make the case for using premium grade fuel, but, in the last few years, the price gap between regular fuel and premium fuel in most areas has risen to $.50 or more per gallon. With the cost of premium fuel being $.50 or more higher than the price of regular fuel, the extra cost of using premium fuel is not insignificant. For a typical driver, using premium fuel over a 5 year period of ownership would add up to over $2500 in extra cost over using regular fuel, and the benefits in horsepower would be, to most, unnoticeable, while the improvements in fuel economy would not be close enough to justify the extra cost.
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mrslnsyder (04-25-18)
04-23-18, 12:56 PM
#120
Pole Position
This is probably the most heated debate on these forums. Do whatever makes you comfortable. I use 87 octane in our 2015 RX450h. Experimenting with the other two levels, I have noticed zero difference in gas mileage or performance. I have used 87 in cars that have required premium for over a million miles and have not had one problem.
I always revert back to two MIT graduates that are car mechanics who had a syndicated radio show called Car Talk for 35 years.
http://www.cartalk.com/content/premi...egular-0#myth4
From the USA Today:
The only modern engines that should really need premium are those with superchargers, which force-feed fuel into the cylinders. "You're driving along and just tramp the gas and the knock sensor cannot sense the knock fast enough in some cases," because the supercharger boosts pressure so fast, says Bob Furey, chemist and fuels specialist at General Motors.
Burning regular when the owner's manual specifies premium won't void the warranty, nor damage the engine, even the most finicky automakers say. "You're giving up perhaps just a little bit of performance that a customer wouldn't really even notice, it's so slight," says Furey.
All this being said to each his own.
I always revert back to two MIT graduates that are car mechanics who had a syndicated radio show called Car Talk for 35 years.
http://www.cartalk.com/content/premi...egular-0#myth4
From the USA Today:
The only modern engines that should really need premium are those with superchargers, which force-feed fuel into the cylinders. "You're driving along and just tramp the gas and the knock sensor cannot sense the knock fast enough in some cases," because the supercharger boosts pressure so fast, says Bob Furey, chemist and fuels specialist at General Motors.
Burning regular when the owner's manual specifies premium won't void the warranty, nor damage the engine, even the most finicky automakers say. "You're giving up perhaps just a little bit of performance that a customer wouldn't really even notice, it's so slight," says Furey.
All this being said to each his own.
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RussLS460 (04-24-18)