Engine Difference Between 2011 And Older

[bigwong]

As I understand, the 2011 ES350 recommends regular gas. The same engine in the older cars had a recommendation of premium. Does any one know if anything different was done to the engine? I know people say they've done comparisons and most stay with premium whereas others just go with the regular, as long as it seems to run OK. With a 30 cent disparity between regular and premium, I've been considering dropping to mid-grade.

[K.C. Dia]

As I understand, the 2011 ES350 recommends regular gas. The same engine in the older cars had a recommendation of premium. Does any one know if anything different was done to the engine? I know people say they've done comparisons and most stay with premium whereas others just go with the regular, as long as it seems to run OK. With a 30 cent disparity between regular and premium, I've been considering dropping to mid-grade.

I use midgrade (89 octane) with my 2010 ES350 with no problems for nearly seven months. Average 30 plus mpg on the highway. Am thinking about trying regular, but can't quite get up the nerve.

[SW03ES]

My guess is theres no change since they amended the HP and torque ratings with the regular fuel...

[bigwong]

Makes you wonder why it was always premium before and not "recommended for more power". Do they think we all have excess money to spend on gas? In other countries where the gas is much more expensive, I would assume the difference between regular and premium would be greater. Is (or was) premium gas also recommended? Just curious.

[wmkim]

IMHO, when I put in gas, I'm paying BP, Chevron, etc.... not Lexus. I'm not an engineer, but if the specifications say "Premium Unleaded Fuel, 91 Octane minimum"...then I'd put that in.

Maybe someone more knowledgeable can jump in but the higher octane fuels (as I understand it) relates to a higher flashpoint for combustion. If you put 87 octane fuel for a car whose engine is made to perform with 91+ octane, then the lower flashpoint/faster rate of combustion makes the engine run less efficiently; therefore, you burn incrementally more fuel which (depending on the car) may negate some of the savings of your per-gallon fuel cost.

My last car was a "Premium Unleaded" vehicle also...when Katrina hit and it disrupted the fuel supply here in Atlanta, several gas stations either had no fuel or only the 87 octane unleaded fuel, so I had no choice but to use reg unlead (at $4.50+/ gallon!). I felt some performance reduction, but barely any change in fuel efficiency; I'm told that the computers in most modern cars can adjust the combustion process to account for the lower octane and you won't get the typical engine knock.

Regarding engine knock... the ES 350 manual (for the 2010) says that you can put in 87 if no premium is available...but that you may experience engine knock, and to put in the premium unleaded as soon as possible or something to that effect.

[SW03ES]

Actually the manual has always said you can run down to 87 with diminished performance. I mean...its a luxury car. I'm sure they assumed that people wanted to get the best performance out of the engine as possible, and they tuned it to do that with premium fuel.

Its a different world nowadays, so you're seeing companies going to regular even with diminished performance.

Do they think we all have excess money to spend on gas?

They think we all are willing to pay extra for the best performance, which is why we bought a Lexus...and not a Toyota.

[amf1932]

Actually the manual has always said you can run down to 87 with diminished performance. I mean...its a luxury car. I'm sure they assumed that people wanted to get the best performance out of the engine as possible, and they tuned it to do that with premium fuel.

Its a different world nowadays, so you're seeing companies going to regular even with diminished performance.

Do they think we all have excess money to spend on gas?

They think we all are willing to pay extra for the best performance, which is why we bought a Lexus...and not a Toyota.

As I mentioned in previous posts that on my previous ES models that I have owned I started to use premium fuel than switched to regular grade. In all these cars I didn't notice any performance changes, pre-ignition, and no changes in fuel mileage.

My 0-60 acceleration was absolutely imperceptible. http://www.cartalk.com/content/features/premium/questions.html#4

[Generally John]

if you can't afford 91+ oct gas, then go buy a toyota

[SW03ES]

if you can't afford 91+ oct gas, then go buy a toyota

Come on, thats neither a helpful or a constructive post.

Being able to afford something isn't whats in question here, its what does the vehicle really require? If it makes you feel special to pay for premium fuel, makes you feel like you're rich or something...have at at.

[jgilbert]

if you can't afford 91+ oct gas, then go buy a toyota

I concur with the Management. Only a fool pays for something that isn't used. I buy regular gas for my M-F rush hour commute 10 miles each way to work because I'm on the freeway and average only about 25 miles per hour. I have never had a problem with regular, by the way. When I am going away for the weekend and will be enjoying the "open highway" I purchase 92 octane.

[Generally John]

What i mean was the car was designed for a certain type of gas. Lexus gets no extra money for the gas you buy, so they must have a pretty good reason to recommend the higher grades of gas.

[SW03ES]

I used to feel the same way, but its not as simple as that. Obviously you eek out a small performance gain using premium fuel (hence why they had to reduce the HP ratings for 2011 vs 2010). but do you HAVE to run premium fuel? Its the same engine as in the Camry...runs regular fuel. Same engine as the 2011...exactly the same...runs regular fuel. So...it stands to reason you should be able to run regular fuel on the 2010.

I've been a long time supporter of using premium fuel, but since this news came out...I've been running regular with absolutely no problem. Only a fool spends money on nothing...and apparently on this vehicle, spending money on premium fuel is spending money on nothing.

[timzter]

I used to feel the same way, but its not as simple as that. Obviously you eek out a small performance gain using premium fuel (hence why they had to reduce the HP ratings for 2011 vs 2010). but do you HAVE to run premium fuel? Its the same engine as in the Camry...runs regular fuel. Same engine as the 2011...exactly the same...runs regular fuel. So...it stands to reason you should be able to run regular fuel on the 2010.

I've been a long time supporter of using premium fuel, but since this news came out...I've been running regular with absolutely no problem. Only a fool spends money on nothing...and apparently on this vehicle, spending money on premium fuel is spending money on nothing.

Wow, are you saying it is OK for me to use regular gas for my ES350 2010??? I know that when I cheated by using regular gas in my previous Infiniti J30, the car experienced "knocking" (http://repairpal.com/what-is-engine-knocking), which made a rattling sound during acceleration, and there was also a noticeable decrease in power, such as when I tried to overtake someone or accelerated from rest at an incline. The Infiniti technician's first question was whether I had started using regular gas! Switching back to premium gas resolved the issue just like that. Are you saying it is NOT a problem for the ES350 2010? No knocking, no decrease in power?

[SW03ES]

So far, no issues here. The 2011 is exactly the same engine, if you can run regular in it you can run regular on the 2010.

[rob_es350]

So far, no issues here. The 2011 is exactly the same engine, if you can run regular in it you can run regular on the 2010.

saw this thread and figured I would give it a test..been putting regular in my 2011, so I waited til the tank was virtually empty, and filled it with premium..couldn't tell the difference, and I drive it pretty hard, so unless my gas station threw regular in their premium tank, I would have to say that you dont lose anything with the regular

perhaps if you did an all out 0-60, but I don't plan on abusing the car that badly, at least now with only 4k miles on it

off topic a bit, but the gas tank is toooo small at 17.5 gallons..ok on highway where mileage seems to be about 26mpg, but local driving is about 18.5 for me, so range is only about 300miles...always in the freakin gas station...my guess is that they just didnt have room for a bigger tank...must be fine for a camry, but not cutting it for an es

[SW03ES]

Man you do drive it hard. I get 22 MPG city, and 30-32 on the highway and I wouldn't consider myself an easy driver...

[rob_es350]

Man you do drive it hard. I get 22 MPG city, and 30-32 on the highway and I wouldn't consider myself an easy driver...

well, I mispoke a bit regarding highway......"pure" highway, we are the same, 31mpg or so

but local driving is between 18 and 19, so I should take it a bit more easy there..22 is waaay better..good to know that 22 is doable..i'll give it a shot..thanks

[pj8708]

So far, no issues here. The 2011 is exactly the same engine, if you can run regular in it you can run regular on the 2010.

I'm with you SW.

Why doesn't everybody use what they think is best, pay what they think is best and enjoy the drive.

Paul

[420benz]

So far, no issues here. The 2011 is exactly the same engine, if you can run regular in it you can run regular on the 2010.

Is the 2008 basically the same as the 2010/2011?

[SW03ES]

Should be...

As a note, I have switched back to premium. For some reason the engine felt a little hesitant and not quite as smooth on the regular, I switched back to premium for a couple tanks to see if that helped...and it seems to have. All in my head? Maybe.

I'm going to try mid-grade.