1GR-FE Reg Unleaded vs Super Unleaded HP Gain???

Naah - screw it and drive it like you stole it! LOL

 

Sensitive buttocks to feel +3 hp >> more likely to be butthurt.

 

Seriously though, run 91 if your engine sounds like something off the Beverly Hillbillies or if you install the TRD supercharger. Otherwise you'll likely be looking for a new motor soon enough.

 

I used to live at about 4000 foot altitude premium fuel was 91 and regular gas was 85. Now that I live near sea level premium is 93 (94 is available at some stations) and regular is 87. I couldn't even find 93 at 4K foot. That certainly reflects a fact that, all else equal, an engine needs lower octane fuel at higher elevation.

Ethanol is higher octane than gasoline and, indeed, has less energy per unit of measure. But it (ethanol generally, higher octane specifically) does allow the engine management computer to NOT pull back timing under heavy loads (to prevent knocking, and engine damage) at the expense of reduced power output.

There's an excellent read on gasoline at the following location, for those inclined:

http://www.faqs.org/faqs/autos/gasoline-faq/

 

There used to be all kinds of gadgets on the market to make more HP or to save fuel weird things that went under carbs that made the fuel "mix" better or magnets attached to fuel lines to "ionize" the fuel and 75% said they could tell the difference in power instantly or they got 10 more miles per gallon more so because they wanted too. Strangely they are no longer around. High test fuel in something that is turbo/super charged is necessary for many reasons the biggest is because compressing air makes it hot razing cylinder temps and the probability of spark knock. If your truck “feels” better with 93 or you just dropped a mili second in the quarter mile than by all means switch to 93 it is your truck and your money. If your truck spark knocks it shouldn’t, Toyota seems to have a fix and I would like to know what the re-flash is really all about is it an engine re-map or did they change the transmission shifting and lockup too?

 

for the people who are saying its a waste of money to buy premium, there is this fact- toyota used to recommend premium grade in the owners manual. I know my 09 doesn't say anything about it so toyota change it at some point before 09 but there was a line in the owners manual that said something like " for best performance, use 91 or above".

I wonder if toyota change it just so people wouldn't complain about needing to use premium gas, or if there was something changed in the ecu.

 

Probably something like that. Even on my Nissan Juke it used to just highly recommend 91 even though the engine ran like absolute shit on 87. My moms friend had one and kept taking it into the dealer because it ran shitty on farm gas and she refused to use 91 .

 

So I completed my test of Unleaded vs Super this week. I ran one full tank of each fuel through the truck under similar driving conditions; a mix of freeway and around town with no off road. Conclusion: No appreciable difference except cost. Mileage was near identical and I did not notice any difference in power. This may sound crazy but it "felt" like regular unleaded actually performed slightly better, both in mileage an power but it was so slight that it might just be perception as opposed to reality. So, my vote is save the $$$.