4GS Fuel discussion Premium or Regular Gas? (merged threads)
06-27-13, 01:38 PM
#121
I've alternated fill-ups on my 87 octane recommended ES, between 87 and 93. After 4,500 miles I've noticed absolutely no difference in power, or fuel economy between the 2 grades. I'll probably switch to 100% 87 octane soon and save the .45/gal.
06-27-13, 04:52 PM
#122
Lexus Fanatic
The Lexus tech rep talked about this last week and said yes Lexus does state running the RX and ES on 87 grade fuel, but he recommended 89 and even 91 grade. He said it was false economy, 87 grade fuel will yield lower hp and lower the exhaust system life. Of course if it is not your car, do what you want.
I had a 2010 ES, and it ran exactly the same on premium and regular. Same economy, same performance. The only difference was a fill up with regular was cheaper. Any difference is just a mental thing.
06-27-13, 05:36 PM
#123
That just doesn't make any sense. The manufacturer reccomends regular, yes the HP is down slightly, from 272 to 268. I have had Lexus vehicles upwards of 12 years and 200,000 miles, and I have never had an exhaust system leak or perforation or any need to replace any component of the exhaust system, nor do you read about issues like that here in the forums for the older cars...so I'm not sure what "reduced exhaust system life" is. No mechanic will tell you to run premium when the car is designed for regular, and the ES and RX are designed for regular.
I had a 2010 ES, and it ran exactly the same on premium and regular. Same economy, same performance. The only difference was a fill up with regular was cheaper. Any difference is just a mental thing.
I had a 2010 ES, and it ran exactly the same on premium and regular. Same economy, same performance. The only difference was a fill up with regular was cheaper. Any difference is just a mental thing.
Zicogold would do well to avoid the Lexus tech he talked to. There is no way the grade of fuel can effect the exhaust system. Also, running a higher grade of gas than recommended is a total waste of money.
I run premium in my GS because the difference in price from regular is small and I drive the GS in a more "spirited" manner than I did the ES. I do believe however, that regular would not harm the engine at all.
Pete
06-27-13, 08:27 PM
#124
This topic came up in a "know your car" presentation at my dealer this week. A couple of RX350 and ES owners were saying that 87 grade is ok to use. The Lexus rep said you can use 87 but the engine will knock (not a good thing) and you will get reduced horsepower and potentially greater fuel consumption. He recommended a minimum of 89 grade for their cars and 91 preferred. He then went on to say with the direct injection engines it is really not an option and 91 grade is the fuel to use.
06-27-13, 11:21 PM
#125
Driver School Candidate
I have always used premium in all my vehicles (its just a habit). And no matter what kind of vehicle it was when I ever went to regular for any reason the engine didnt like it as much. I tried to make a point earlier about preimum being a higher quality fuel and why it is better for an engine. Sticking with the engineeres recomendations is going to be the best. But, using premium will always benifit the engine (life wise and overall power and better operating quality, i.e smoothness, etc.). And if an engine is recommended to be ran on premium (a higher compression engine, as I have mentioned before) using a lower grade/octane fuel may not be damaging to it right a way but, the engine will not like it and eventually it will start to hate it. All I'll say is, if you care for your car and want to treat it with the best and pamper it and hopefully have it last a long time for you than take care of it. Give it what it wants and likes and it will give you the same. That's what I believe and my vehicles have always been good to me.
06-28-13, 09:16 AM
#127
Since 2012, Lexus has recommended 87 octane for the RX350.
Both my friends, the auto engineer (Ford) and the chemical engineer (Suncor) have in the past corroborated what was presented by the Lexus rep. I realize this contradicts what is stated in the printed material, but I guess we make our choice and live with it.
You should have seen the look of confusion on the faces of the RX and ES owner in presentation.
06-28-13, 10:48 AM
#128
Wow! So much controversy over a simple question. Good job Stew! LOL
06-30-13, 08:26 PM
#129
Lexus Fanatic
Originally Posted by HopVIP
I tried to make a point earlier about preimum being a higher quality fuel and why it is better for an engine.
You aren't going to hurt anything by running premium, if it makes you happy go for it...but the goal of this community is to provide factual information to the membership so they can make informed choices. The facts are:
1. The 3.5L V6 in the ES & RX application is designed to run on regular fuel as of 2011. Prior to 2011 it was designated to run on Premium fuel with slightly enhanced HP figures. This same engine is also used in several Toyota applications designated for regular fuel. As per Lexus and Toyota, running regular fuel is fine for this engine.
2. Premium fuel is not higher quality than Regular fuel. The difference lies in the octane rating, one is designed for higher compression applications and one is not. Using higher octane fuel in a lower compression engine does not enhance power or fuel economy.
Those are facts. If someone still chooses to use higher octane fuel in a vehicle that is not designated for it because it "feels" better thats their prerogative, but facts are facts.
06-30-13, 09:29 PM
#130
Guest
Posts: n/a
GS needs premium. Some new Lexus models don't. I used to track and complain about gas then I Grew up. As much as I love cars I walk and take the train/trolly tons.
There are some odd fuel requirements on some cars FYI.... It's surprising...
07-03-13, 09:43 PM
#131
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Those following this thread might find this article interesting:
http://www.nytimes.com/2013/06/30/au...osts-more.html
“As we continue to reduce the displacement of the engine, the customers’ expectations of the performance of the vehicle aren’t changing,” Doug Skorupski, technical strategy manager at Volkswagen of America, said. “So you have to run higher and higher boost pressures from your turbochargers, and as you do that, higher octane plays into it.”
Engineers have several tools to prevent engine knock, but there’s no cure-all. Knock sensors, which can signal the engine-control computer to delay the ignition spark when detonation is detected, inevitably cut back performance. Owners of cars that carry a premium-fuel recommendation can safely operate their vehicles with regular unleaded fuel; however, the engine will lose roughly five horsepower and one to two m.p.g., Mr. Skorupski said.
“You are reducing your fuel economy and your performance, but there is no detrimental damage to the engine,” he said.
Another increasingly common technology, direct fuel injection, sprays gasoline into the cylinder at high pressure; the cooling effect of the atomized gasoline helps to keep knock in check. In effect, direct injection tricks the engine into thinking it is running a higher-octane gas — up to four to six octane numbers, Rick Davis, a combustion specialist at G.M., said.
Putting regular-grade fuel in a car for which premium is required, rather than just recommended, is far riskier, experts say. “Under extreme driving conditions, the engines aren’t necessarily protected from degradation or damage if somebody used regular fuel,” Mr. Davis said.
http://www.nytimes.com/2013/06/30/au...osts-more.html
“As we continue to reduce the displacement of the engine, the customers’ expectations of the performance of the vehicle aren’t changing,” Doug Skorupski, technical strategy manager at Volkswagen of America, said. “So you have to run higher and higher boost pressures from your turbochargers, and as you do that, higher octane plays into it.”
Engineers have several tools to prevent engine knock, but there’s no cure-all. Knock sensors, which can signal the engine-control computer to delay the ignition spark when detonation is detected, inevitably cut back performance. Owners of cars that carry a premium-fuel recommendation can safely operate their vehicles with regular unleaded fuel; however, the engine will lose roughly five horsepower and one to two m.p.g., Mr. Skorupski said.
“You are reducing your fuel economy and your performance, but there is no detrimental damage to the engine,” he said.
Another increasingly common technology, direct fuel injection, sprays gasoline into the cylinder at high pressure; the cooling effect of the atomized gasoline helps to keep knock in check. In effect, direct injection tricks the engine into thinking it is running a higher-octane gas — up to four to six octane numbers, Rick Davis, a combustion specialist at G.M., said.
Putting regular-grade fuel in a car for which premium is required, rather than just recommended, is far riskier, experts say. “Under extreme driving conditions, the engines aren’t necessarily protected from degradation or damage if somebody used regular fuel,” Mr. Davis said.
07-04-13, 09:09 AM
#135
Lexus Fanatic
Yeah seems pretty clear to me LOL
