told not to use anything but regular gas..... true?

The best gas I used was in July 2012 when we went to Reno on vacation. I filled up in Carson City and the
tank was quite low and took a little over 10 gallons. The station was a store / mini-mart, no name gas
and I filled up with regular and there was no mention anywhere on the pump of 10% Ethanol as
there is in Oregon. The price was about 10 cents a gallon less other stations.

After filling up and driving a few miles I noticed an immediate increase in MPG's. I noticed I was getting at
least 5 mpg's more than with the gas I had purchased in Oregon.

That tank I got close to 60 mpg even after climbing up to Lake Tahoe and Virginia City.

Quite possibly it was because there was no Ethanol in the gasoline.

 

Mike (We0H), I'm wondering if this "cold start knocking" is caused due to the C/R? And owners using 87?
I use 87 on mine but nothing but the Top Tier Gasoline Top Tier Gas brands has ever gone down my filler neck

 

Have you simulated the conditions in which some of reliably get the cold start knock? I've only had the knock the one time I staged the car to meet those conditions.

 

I use mid grade 89 octane and premium octane 90+ during the winter season due to the winter blend mix they use here in Virginia. I’ll switch back to regular 87 octane during the summer months.

 

Interesting........... Have you noticed an increase in mileage using 89 octane or higher during the winter blend season? I work with Mark Knight who previously posted about increased mileage using 91 octane. We discussed the increase and I was wondering if it had anything to do with the winter blend in the 83 octane.

 

Well let's just say I'm maintaining an average around 48 to 51mpg during the winter months using a higher octane. Summer months I'm usually stay above 54mpg. A lot of people will argue the facts on whether or not to switch to a higher octane during the winter months. It really just boils down to the individual and their peace of mind. Higher octane will not hurt your Prius regardless of what people say. Is it a waste, probably so, I figure I'm still saving money either way I use to own a 2007 Tacoma that only got 18 to 22 mpg.

 

'Winter blend' is richer in volatiles, so it starts easier, while' Summer blend' is poor in volatiles, to avoid vapor lock from boiling. Winter blend in summer would evaporate too easy causing pollution and poor driveability, Summer blend in winter would not start.

The Prius seems to do worse on winter blend, but I am not sure anyone has run a blind test versus outside temperature. In general, the Prius hates cold.

Octane is a red herring, the Prius never needs more than 87 unless you can hear it knocking.

explanation with an ecological bias
Summer-Blend vs Winter-Blend Gasoline: What’s the Difference? - Popular Mechanics

explanation with a performance bias
THE TRUTH ABOUT WINTER GAS. BY JOHN HUNKINS

 

One tank of each means nothing. If there is a consistent difference after alternating at least ten times, that starts to be significant.

If the engine knocks it needs repair, not higher octane.

 

It's the opposite, at Canadian Chevrons in my area at least: their Premium is the only gas without ethanol.

Regarding all your other points, spot-on: higher octane gas is only needed to prevent pre-ignition in few-and-far-between higher ignition engines. You wouldn't glean that though, rolling into a typical gas station, where 2/3 or 3/4 of the pumps are for this minority...

There's a recent CBC MarketPlace show on the subject:

Pump Fiction - Marketplace

 

We don't have winterblends here for gasoline....only for diesel.

We have 95 octane, 98 octane and V-Power. V-power is 97 octane and has GTL fuel blended in.

Low octane in high compression engines (without knocking sensor) can cause knocking.

High octane in a Prius won't hurt your engine....only your wallet.

I know a little bit about those things because I work at the largest refinery in Europe and was for 1 year at the start-up of the largest GTL plant of the world in Qatar.

Luckily I get 20% off at Shell stations....we have to pay around $8/gallon here....

 

As have all my previously and currently owned ice vehicles. Just another side effect of living in the snow belt.

 

Not to go completely off topic, but I would like to ask if is it ok to input near max level of gas or "topping it off." On my old car, I would just wait for the gas handle to click and then try to round it to the nearest dollar.

 

Some will say fill 'till she clicks, and others will say fill 'em how you like. I have filled my vehicles to the threads and never had any issues with carbon canisters or any issues at all other than I get to drive a bit further on the tank. First click on a 3rd Gen is about 2 gallons shy of full to the threads. That's a hundred miles worth of driving.

Mike

 

Thats what I have always done, no problems.

 

New E15 Gasoline May Damage Vehicles and Cause Consumer Confusion | AAA NewsRoom

 

Yea! isn't it great, gas for almost nobody. Nobody should use this stuff.

 

The stock 3rd Gen ECU tune can handle E50 with no codes set, but Toyota might have to do sumthin else to run them on E15. Has anyone actually done their own testing on the various E blends to see at what point if any issues crop up? All I know is a bone stock 3rd Gen runs just fine on E50. I have never taken the fuel system apart to have a look and I know nobody that has done so to their own vehicle. There are a lot of people that post what they have read online, but can anyone show us actual pics and other data to back up what they found themselves? A 3rd Gen with some changes averages 46 mpg combined running straight E85

Mike

 

Toyota said E 15 will void warranty article on yahoo yesterday along with other mfg's. Please correct me if I read the article wrong.

 

You are correct

Mike

 

Link to e 15 and warranties.
Warranties void on cars burning E15, say automakers