Premium fuel pros for es300- none, cons- thinner wallet. 87 octane pros for es300- more money to spend on other things and the car should run fine, cons- if the motor develops pinging you should go for higher octane fuel. Fuel additives as in a quality injector cleaner added to the tank need to be used only every 3,000 miles. Do not buy the cheap cleaner that is supposed to be used every tank full, as you are only wasting your money. Berryman's brand is a good quality injector cleaner to use every 3,000 miles.

 

I found a measurable improvement in gas mileage with premium, but didn't notice anything with fuel injector cleaner in the gas.

IMO for the 1MZ/3MZ Toyota engines, put the extra $10 per tank on synthetic oil rather than premium gas.

 

I really don't understand why there must be a new thread every week on what octane gas to use.

 

It wasn't on what octane gas to use, it was comparing the benefits or negatives of premium vs regular WITH the additive. I searched for a thread like this, there was none.

Nonetheless, thanks for the replies.

 

How about premium gas WITH fuel additives.

Now the grass is greener on both sides.

 

There is in fact many threads which mention the use of an additive (octane booster, fuel injector cleaner , etc). You did not look close enough.

You also did not need to create a new thread, if you honestly believed no thread mentioned additives (which they do) you could simply added a post to one of the billion threads on this subject and asked the simple question of would additives take the place of running high octane gas.

But I digress, apparently no one cares about trying to keep the forum organized and easy to find relevant information.

 

I am just a newbie to this forum but I have to say, I look hard and do searches before I ask my question but people should not be afraid to ask something - even if it has been asked before. It is a "discussion" forum after all. If it is indeed a topic someone has already read about then why click on it to read it? Just my 2 cents.

 

The problem is not with asking a question, please don't let me discourage you from that.

The issue is with creating multiple (i.e hundreds) of threads on the same topic. If you have a comment please reply to the old thread. This way when someone goes to search all of the information they need is in one thread.

If there is 10 billion threads on one thing, it's going to be incredibly difficult to filter out the junk from the actual threads that have real information.

 

If you're putting the additives in regular fuel just in order to increase octane, you'd come out cheaper buying premium fuel instead. If you're using it as a fuel system cleaner, then occasional use will be sufficient, especially if you're using name brand fuel.

As for any performance or fuel efficiency increases, I've found very little improvement in either from using premium in any of my three ES's, a 97, a 2000, and a 2004. My suggestion is check it out for yourself, just try to be objective and compare apples to apples and don't make any generalizations from one or two tanks. Things like engine smoothness and pickup are subjective and can be influenced by your expectations of what you think it should be. If your mileage isn't affected then you can assume that normal performance isn't going to be affected either. Unless there is obvious knock then you're not going to hurt anything by using regular, and testing it yourself is only going to cost you a few bucks a tank.

There is no reason for fuel additives to have any significant effect on engine wear.

 

Actually, too much fuel additives, or the wrong additive, (such as octane boosters for example) can Severly damage the Catalytic converter.

 

So, after reading many threads and articles about using different octane ratings and MPG loss/gains, it seems it's quite a mixed bag. So here I am, scratching my head.

For a study of my own, I decided to go through a few tanks of 89, then try 87 (recommended). Results were:

89 - 22 MPG
87 - 15 MPG

Both were done with the same driving habits, both filled up full. So, why do I get much better MPG with 89?
From what I've heard, the higher the rating, the "cleaner" , or more "pure" the fuel; does this mean I should clean out my fuel injectors? Being at 113K, I think I should anyhow.

Any kind of relevant insight/experience on this, please do tell.

 

Something is wrong with how you calculated mpg. That's quite a large difference, a different octane level would not have an impact that large. It's true there is an impact, but more along the lines of as much as 2 mpg + - .

I however do recommend using high octane fuel in these high compression 1MZ-FE & 3MZ-FE's.

 

I agree something isn't right with the numbers... hell maybe they are correct but then I would argue driving conditions weren't similar. I only see the 2 MPG +/- when I switch from 87 to 91 not 89... don't know many people who use 89

 

I didn't have enough funds at the point in time to fill up to the brim, so I compensated by adding a few gallons to the amount I actually filled it. Guess I was short some gallons.

I am running it with 89 at the moment. I notice better performance and MPG. It seems that higher rpms are less than usual in their fuel consumption. What is the most efficient/best performing octane? Should I try 91?

 

Honestly there are numerous threads on here about mpg and which type of gas to use, and you'll get a bunch of different answers so I suggest you do a search and read all the information for yourself and make a decision for yourself based on what you read and your own personal experience.

For me personally, I only was willing to pay the premium for 91 when I was driving mostly highway (70% and up) when I first got the car but now that I drive city for about 90% of the tank, I see no benefit to putting in 91. I only experienced better MPG at higher and constant RPMs. For sitting in city traffic 91 did absolutely no better than 87. That is just my experience.