Same here. When I put 91 in my ES, it's more responsive than 87 or 89. And my SC is always 91. I spend $30 for a tank on the ES and about $50 on the SC. I usually go to shell for v-power. I heard v-power has 5 times the detergent than the recomended level for standard gasoline. And shell regular and plus has 2 times the detergent than standard gasoline. Sometimes I use octane boosters/valve cleaners. STP is better than Prestone.

 

Ya, but the thing about gas detergents is that they're weaker than they were a few years ago.
All of them had lots of detergents in them up until a few years ago, then the government siaid hmmm that's a great idea, we'll required they use some! The problem is they set the requirement many times as low as the gas already had - so everybody backed off the detergents :'(


Yick. Techron, or Seafoam it.

 

I have run both 87 and 89 in my 98 ES300. While I understand "what the book says" and "you don't need anything above 87" etc. etc. I recently took a trip of approx 900 miles one way (plenty of time to average) and found that my car got 1.7 mpg better with the 89. I am a sales rep and have compared many times with different conditions - and still run 89.

In real world conditions, especially with cars with some mileage (carbon builds up) plus the fact that fuel can vary slightly in actual octane rating from station to station and day to day, I would recommend mid-grade, unless your car recommends premium (I didn't know any of the ES line recommended premium), but anyway.........

When carbon builds up over time (and yes it will to some extent), the combusion chamber is actually reduced in size slightly. This compression increase along with the "hot spots" on the carbon deposits causes most vehicles with ping slightly (or not so slightly) with 87. This may not harm the engine in the short run, but what I have experienced is that the ECU will detect pinging before it is audible to most people and retard the timing in an attempt to reduce the pinging. Retarded timing = reduced fuel mileage. This could my mileage increase with 89 over the 87. I have not run 93 octane and probably will not. I would recommend crunching some numbers to see the % in increase of fuel mileage for both and compare that to the % difference in gas pricing. As gas increases in price the % difference is reduced and it becomes a better bargain to run a higher octane fuel.

I am not disagreeing w/ anyone elses opinions, just offering my experiences. To me, it's not worth saving a couple of dollars to put the absolute cheapest fuel in my tank. Oh yeah and I would recommend only using name brand fuels.

Pinging is not a "normal operating condition".

 

Try this website and see what you think. It is a standard for detergent content that has been adopted by several manufacturers including Honda, BMW, Toyota, and GM.

http://www.toptiergas.com/

The brands of gasoline that meet the standard include the expensive Shell and Chevron brands as well as cheap ones like QuikTrip. Car and Driver magazine printed an editorial a few months ago about this standard, I believe it was written by Larry Webster.

I'm not too concerned with using anything other than 87 for long-term durability of my engines, and judging from everything I've heard and read about the potential efficiency benefits of higher octane, I think the potential advantage is too slim to bother with. To decide which would be the most cost effective, I'd have to factor my past mileage, the weather, the type of driving I plan to do in the next week, and today's price at the pump. If it were that important to me, I'd buy an economy car that gets 28 mpg and only takes regular.

 

Good information for sure, ESPilot.

Concerning your last statement; that was one of the points I was attempting to make - over time even if a vehicle is designed for 87 octane, MY experience has been that ANY vehicle will get slightly better fuel mileage with 89 octane (at least every car I have owned). I am talking about a car with some mileage. Many studies and published data are garnered from information gathered in laboratories with new cars.

There is a lot of information on the web and many opinions. Again, I just passing on info based on my documented mileage in various conditions, etc. etc. I travel approx 30 - 35k a year and have tried numerous brands and octane ratings on many different vehicles. I am not basing my opinions on what others say and think might be a possibility.

For comparison, the calculation is very simple (% premium in price of 89 vs 87) compared to the mileage I get with 87 vs 89. If gas is $2.50 / gal (plug your own number here) for 87 and $2.60 for 89 (typically a 10 cent diff) the cost difference is 4% (as the gas prices increases, this % is even less). My vehicle consistently gets about 1.7 to 1.8 mpg more with 89 octane fuel; a mileage difference of 6% (based on 27.3 mpg vs 29.0 mpg). Plus I don't have to worry about any potential detrimental effects of spark knock over the long or short term

 

If it's consistently a ~2%+ cost savings, then I would have to agree that you've made the smart choice. It's been a while since I bothered recording mileage, maybe I should try it again...

 

Hey ESPilot do you have oxygenated fuel in AZ? I used to live in NV for about a year and noticed that the oxygenated fuel potentially amplifies the problem since it burns hotter. Your mileage might actually be higher % better than mine with 89.

Just for info, I did not notice any mileage difference on my current ES between 89 and 93.

 

Oxygenated = Bllllah
Gasohol = NEVER, Never, never, never ,never, never run any gas with any amount of ethanol in it.

 

I haven't seen "oxygenated", I'll watch for it next time.

 

damn phoenix how are u getting 375miles per tank?!?!!??!

im getting barely 215 miles per tank right before the empty light comes on.

granted i just got the car and i'm doing alot of city driving. Also, i havent cleaned it with seafoam yet.

but damn 215 miles divided by 18.5 gallons = 11mpg! I tried both regular fuel and premium fuel. They both yield similar results. =/

I'm thinking about doing a motorvac to clean the rail and the injectors when i go back to skool next week. (im an autotech student so i get to use the machine for free)

Is doing motorvac or seafoam the same? or would u recommend doing both?

Thanks.

 

Because it's like an 18.5 gallon tank & I normally fill up @ 16.5 gallons left.
Every v6 so far get's a combined 20-25mpg depending on condition & how you drive!

Motorvacs work but are expencive & they don't really help the fuel systems 2 much, Denso/Toyota fuel ystems honestly don't need any real help. It's pretty rare they clogg. Just buy like 2 cans of seafoam & do the intake a few times.

 

I bought a 2006 ES in November and the owners manual actually states to use 91 Octane or Higher. Is this Correct? Or can i use 89

 

 

My 02 has just under 100k on the odo and I have been using 87 octane without issue since I got it used this past summer. Whenever I have to give it gas all of a sudden though I do get a rattling noise for a moment and then it goes away quickly. Guess it is time to upgrade the gas to a higher octane after reading this thread.

 

Yep. Thaaaat be a good idea since you can't retard your ignition timing without either:
A) Buying a piggyback
B) Re-aligning the crankshaft posision sensor



You could try to do a can of seafoam in the intake. If you've got lots of carbon build-up (You should have) sometimes that can put you over the edge with pre-ignition. The carbon turns white-hot & can ignite the fuel early.
You could also drop to a grade weaker spark plug that's not as hot. You'll probably loose a couple horsepower, but that *might* get it too.

Buuuut those are kinda out there a little bit. I mean.... If you had a lotta power, or a turbo/SC it'd work, but maybe/maybe not stock N/A. Just throwing it out there.


Tooting my own horn... Because I can!
maniax I set the mpg record for a 3vz-fe AFAIK @ 28mpg -420 miles on a tank. I went on a trip to the smokies last spring after I had done all the mods, got the car running - it leaned it out & I installed water injection.
Kinda cheating tho... It was 100% highway cruising @ 70mph. Seriously... Fill up, get on the interstante & nap.