I agree Vforce, its like buying a $50000 car and putting in Kmart brand engine oil. To me, 89 octance makes even less sense than 87 octane. If you out in 89 instead of 91 ocatne and fill up once a week, with 91 octance costing 15 cents more per gallon, you save a only $140 a year. Thats assuming you do not get better gas mileage with 91 octane.

 

Actually, if you look at the full analysis of the creation of ethanol like they do primarily in the US (from corn), they use more than one gallon of petroleum to create one gallon of ethanol. And that doesn't even go to mention the destruction of waterways and land from the pollution created for corn fields in arid areas (which was done because the price of corn was so high, farmers had dollar signs flashing in their eyes).

Besides the amount of water necessary to grow corn and the energy necessary to distill corn into ethanol, as a water-soluable product, ethanol cannot be carried in the existing pipelines in the US, so it has to be trucked all around the country. Then consider the decreased efficiency of ethanol (I believe it has 20% less BTUs than gasoline - I recall that E85 cars get 20-25% fewer MPGs on E85 than on straight gasoline).

The current ethanol regulation is a SHAM forced on us by farm state politicians, who we are already subsidizing with outrageous farm payments.

That being said, with its higher octane, it can be controlled in high compression engines better (which is why you see it in F1 and top fuel dragsters). And if you look at a country like Brazil, with its sugar cane ethanol industry (which in recent years started destroying the rain forest for farm lane), they are independent of oil imports. If someone figures out how to make cellulosic (essentially, wasted parts of plants like stems and leaves, as well as grasses) ethanol efficiently, that would be much, much better. MTBE (the petroleum-derived additive that used to be in gasoline until it was outlawed) was evil when it leaked from underground fuel tanks, but it really helped clear up the air quality.

Nothing is perfect, but the status quo was much better than the current ethanol regulations.

 

We use 89 oct. in our -04 RX but 91oct in our 07GS.

 

Esso premium gave the same millage. however this was all city driving. top speed 70kmph and average speed 40kmph. 62 liters for 422kms. filled it up with shell v-power 91 with nitrogen today. engine sound got even better. will update on millage after next fill. i am going to fill the next tank with husky/mohawk gas which has 94 octane and 10% ethanol. will be interesting to see the out come.

 

I'd be interested to know how you fare with Shell, because I tried Shell again and lost mileage with it on 93 octane with nitrogen. I have gone back to Chevron.

 

If you want the best economy and the best performance you WILL ONLY use the recommended grade. If you want the car to run (it will) with worse performance, worse economy and more pinging, be my guest and get the cheapest gas you can find.

You won't save a dime b/c you will lose fuel economy.

 

Chevron all the way. That's what I've been using for years. A buddy of mine did some research and found that Chevron was the best overall gas to use especially in the long run...

 

One other one that I like that's really tied with Chevron in my opinion is Sunoco. I used to get my hands on it when I was in Mexico (but a very high cost) through our racing gas importer, and used to run some of both their 93 octane and 100+ octane racing gas about once every 6 months. Chevron stations are closer to where I live, but I do use Sunoco when I need gas and I come across it.

Mobil has also worked acceptably well for me, but not quite as well as Chevron and Sunoco.

 

The shell Nitro premium came at 440 kms with 62 liters. engine noise is ok.

 

Keep in mind a new engine needs a slight break-in period. I'm sure the same gas used over the first 1000mi would yield slightly different results each fill up...so changing brands weekly may not indicate that much.

 

my brother has run pipleine companies for years. He tells me gas is gas in general--when the company trucks pick up gas at terminals, thats when they put in the specific additives for each company.

So the differences are 1) Octane, and 2) additives.

when you find the name brand you like you can stick with it--I stick with shell as I have a discount shell card and the station is near the house

 

The cars will run on the lower octane fuel, but performance and fuel economy will be less. Running the good fuel can increase your fuel economy by as much as 4-6 miles per gallon. Resulting in spending less on fuel in the long run. The more expensive gas gets the delta decreases. No matter how expensive gas gets it is always about .25 more for the better gas. The more expensive gas gets the percentage to run the good gas gets smaller and smaller.

 

Here is some evidence to the contrary:

Toyota Land Cruiser, regular gas:
13/18/15 mpg

LX570, premium gas:
12/18/14 mpg

This isn't a perfect comparison because while the engines I believe are exactly the same, the LX does weigh 5% more. But if what you said about the mpg advantage of premium gas were true, one would still expect the LX with premium to get at least as high mpg as the TLC with regular. Instead, we see the opposite...the TLC gets slightly better mpg, making me think that the extra octane has little or no benefit, mpg-wise.

If anyone knows of better examples than this, where we have EPA numbers for premium and regular for cars that are closer to being identical, I'd be interested in seeing the numbers.

 

Use the best.
Besides better Mileage it is just plain better all around. Of course I say this because we pay 10 cents more then regular on Mondays at our local station.

 

back several years ago when ethanol started to be mixed in with "pure" gas I experienced a noticable drop off in mileage.

Yet another inefficiency to the corn based fuel.