What fuel grade is everyone using on their 2012-2015 RX?
#33
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
https://www.clublexus.com/forums/7037262-post9.html
Eric
#34
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
..very interesting......but if I had 2011 model I will have some concern with prolonged "pinging", it is not only a nuisance but could also cause long term damage to the engine, but since the letter came from "the horse's mouth" we should take it as it and save it just in case....that is what I would do....
#35
Lexus Test Driver
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
So the answer is Yes and Yes. It may not be leaps and bounds but, using Premium does make a difference. The difference between reg and premium here is 20 cents. Never in my 40 some yrs of driving have I put reg gas in any car I have owned. Just a thing with me and I am not in the poor house for doing so.
![Stick Out Tongue](https://www.clublexus.com/forums/images/smilies/tongue.gif)
#36
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
Having driven and studied cars since 1960 I have had engineers in recent years say the engine will adjust for Premium and put out more power and better gas mileage. I see it as every time I drive to Las Vegas I put in premium and I only drop from High gear on two hills and I DO get better gas mileage!!! Around town I put in Regular. By the way, I also always put in Top Tier gas when buying premium!! www.toptiergas.com of which Lexus was one of the first to join in!!
#38
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
on another note, I am not trying to be controversial...just a different opinion...
#40
Lead Lap
iTrader: (5)
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
when a factory car requires premium gas it is because the higher octane in the premium gas prevents detonation (where the fuel/air mixture combusts BEFORE they are ignited by the spark plugs.) i think i read that this is because the higher octane keeps the cylinders cooler.
87 vs 89 vs 91/93 giving more or less power has been argued/bickered/etc about for years and years, and will continue to be argued about.
in many peoples opinion, the gain in power from these lower to higher grades is negligible. you really have to start going much higher than that to truly see power.
the only thing that could be suggested would be to buy 'top tier' gas, which is supposed to have higher amounts of detergents to keep your engine running 'cleaner.' (ie 76, chevron, shell, etc) cheap gas is usually not good gas.
87 vs 89 vs 91/93 giving more or less power has been argued/bickered/etc about for years and years, and will continue to be argued about.
in many peoples opinion, the gain in power from these lower to higher grades is negligible. you really have to start going much higher than that to truly see power.
the only thing that could be suggested would be to buy 'top tier' gas, which is supposed to have higher amounts of detergents to keep your engine running 'cleaner.' (ie 76, chevron, shell, etc) cheap gas is usually not good gas.
#41
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
the only thing that could be suggested would be to buy 'top tier' gas, which is supposed to have higher amounts of detergents to keep your engine running 'cleaner.' (ie 76, chevron, shell, etc) cheap gas is usually not good gas.[/QUOTE]
Totally agree....
Totally agree....
#42
Instructor
iTrader: (1)
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
Having driven and studied cars since 1960 I have had engineers in recent years say the engine will adjust for Premium and put out more power and better gas mileage. I see it as every time I drive to Las Vegas I put in premium and I only drop from High gear on two hills and I DO get better gas mileage!!! Around town I put in Regular. By the way, I also always put in Top Tier gas when buying premium!! www.toptiergas.com of which Lexus was one of the first to join in!!
The idea that the cars knows what kind of gas is in it is something I've read numerous times on the internet and speaks to a lack of knowledge of engine management.
High compression and forced induction motors generally require premium. They need it to prevent knock. A Corolla....just doesn't. You're throwing away the money.
I've had my sales rep tell me repeatedly that my 2010 RX350 doesn't need premium. The 2GR-FE has 10.8:1 compression, which is high for regular. I've done test runs with regular gas and seen no difference, but I'd rather just put premium in it. I plan on keeping the truck after the lease is out.
#43
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
False. If I put premium in a car with a moderate compression motor, there is no sensor that detects the octane level of the gas and ADDS timing. Can't do it with the O2s either. If I put regular in a car designed for premium, the knock sensors will sense knock and pull timing.
The idea that the cars knows what kind of gas is in it is something I've read numerous times on the internet and speaks to a lack of knowledge of engine management.
High compression and forced induction motors generally require premium. They need it to prevent knock. A Corolla....just doesn't. You're throwing away the money.
I've had my sales rep tell me repeatedly that my 2010 RX350 doesn't need premium. The 2GR-FE has 10.8:1 compression, which is high for regular. I've done test runs with regular gas and seen no difference, but I'd rather just put premium in it. I plan on keeping the truck after the lease is out.
The idea that the cars knows what kind of gas is in it is something I've read numerous times on the internet and speaks to a lack of knowledge of engine management.
High compression and forced induction motors generally require premium. They need it to prevent knock. A Corolla....just doesn't. You're throwing away the money.
I've had my sales rep tell me repeatedly that my 2010 RX350 doesn't need premium. The 2GR-FE has 10.8:1 compression, which is high for regular. I've done test runs with regular gas and seen no difference, but I'd rather just put premium in it. I plan on keeping the truck after the lease is out.
Makes sense that the sensor would be designed to check for a problem as opposed to looking for something positive to adjust to.
#44
Lexus Test Driver
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
False. If I put premium in a car with a moderate compression motor, there is no sensor that detects the octane level of the gas and ADDS timing. Can't do it with the O2s either. If I put regular in a car designed for premium, the knock sensors will sense knock and pull timing.
The idea that the cars knows what kind of gas is in it is something I've read numerous times on the internet and speaks to a lack of knowledge of engine management.
High compression and forced induction motors generally require premium. They need it to prevent knock. A Corolla....just doesn't. You're throwing away the money.
I've had my sales rep tell me repeatedly that my 2010 RX350 doesn't need premium. The 2GR-FE has 10.8:1 compression, which is high for regular. I've done test runs with regular gas and seen no difference, but I'd rather just put premium in it. I plan on keeping the truck after the lease is out.
The idea that the cars knows what kind of gas is in it is something I've read numerous times on the internet and speaks to a lack of knowledge of engine management.
High compression and forced induction motors generally require premium. They need it to prevent knock. A Corolla....just doesn't. You're throwing away the money.
I've had my sales rep tell me repeatedly that my 2010 RX350 doesn't need premium. The 2GR-FE has 10.8:1 compression, which is high for regular. I've done test runs with regular gas and seen no difference, but I'd rather just put premium in it. I plan on keeping the truck after the lease is out.
#45
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
On previous RXs they told me I could use regular. After 4 years the 400h started getting bad mileage and poorer performance and I had to switch to premium even though I always used top tier gas. But on the 2010 they said I really needed to use premium (same service advisor). Ironically, at my last trip to the Shell station the attendant was surprised when I requested premium. Hmm I wonder what other RX owners do. There are zillions in town,