I see many people come on here talking about how they run premium gas in their stock/NA tC and I hang my head in shame a little lower each time. Our manual recommends regular fuel, 87 octane. Why would you run any higher? Do you just want to throw money away? You're not getting any real benefit from it and if you think you are, it's all in your head. Run 87. It's what your car wants.

Now if you're boosted... turbo or supercharged, you should be running Premium (at least 91, I believe). But that is a whole different story and this is all directed at the NA people.

Our manual says the following (pg 234 for 2005MY and pg 236 for 2006MY):

No, this does not mean 91 is actually recommended or ideal. The 91 is just another type of rating system used to determine the pump rating... explained here:

Taken from here: https://www.scionlife.com/forums/viewtopic.php?t=76399

Further Reading:
- http://tinyurl.com/c3dgoe (caranddriver.com link borked by the forum)
- http://www.usatoday.com/money/autos/...emiumgas_x.htm
- http://www.msnbc.msn.com/id/25691323/
- http://www.kiplinger.com/columns/car...4/car1105.html
- http://www.straightdope.com/columns/...nd-regular-gas
- http://www.consumerenergycenter.org/...s_premium.html
- http://www.ftc.gov/bcp/edu/pubs/cons...s/aut12.shtmjj
- http://en.wikipedia.org/wiki/Octane_rating
- http://www.google.com

What You Can Do
If you want better mileage and better fuel for your engine, you don't need to run a higher octane to get it. You would be better off just running one of the so-called Top Tier Gases. These are specific retailers that bring you a higher quality fuel with more detergents to remove/prevent buildup and such on engine components.

More Info: http://www.toptiergas.com

NOTE: If you switch back to regular from Premium, it is possible you could have a rough idle or something for the first tank. I don't know if this is true or not, but thought I'd throw it out here in case someone switched back to regular and wanted to come on here and complain that it's hurting their car now.

 

this is a great write up.

sticky?

 

It already is.

 

Who cares..premium is just one or two dollars more. You can probably find the loose change in your couch or something. If you watch any of the ignition dvds, they show you how premium gas makes a difference. You can actually see a graduate increase and consistency in power over time. Nothing too dramatic but there is a difference none to less. But like you said, premium is not needed..just a preference.

 

another link to add to the list..
http://www.ftc.gov/bcp/edu/pubs/cons...tos/aut12.shtm

and who cares?? i've seen cars perform worse with premium fuel versus just regular 87.

 

Done!

 

I realize it's going to be a preference for some people... and that's fine. But for people to think it's really going to help or perform better, it's not. I'm not sure what videos you're talking about, but I've yet to see any real evidence saying it will.

 

These are all theories..how come we dont see any hard evidence that premium does not make a difference? Ignition dvd provides dynos, real changes in spikes on the charts. Premium is not only known for better performance but it has cleaning agents that regular gas doesnt offer.

 

also.. it's not just octane rating... but actually what brand of fuel.

Toyota recommends Top Tier gasoline.... which yes.. will cost more than your mom and pop gas station or arco...

but there are reasons.. and this time.. legitimate ones.
and those are the cleaning agents.... it's not about octane at that point man..

 

So I'm throwing my money away with the 100/130 avgas? But it smells so good!

 

Sounds like you're talking more about this:

http://www.toptiergas.com/

 

yea... as far as cleaning agents... it's not a matter of octane rating.. more the brand of gasoline you use...

i just mentioned that above ack.. heheh..

 

^ Ya, that's why I went and got the link.

 

Regardless I guess everything just goes back to preferences, my brother has a o7 Lexus GS that recommends premium and he runs regular. Everything runs smooth and fine without any knocking. Had the ride almost 2 years. I do agree that running premium is significantly better for high performance vehicles not stock 4 cylinders but when it comes to me, I just like the preference that my baby is drinking premium gas. I always wondered how anyone would be able to tell the difference at the gas station. I mean for all we know, Shell or VP could just put regular in all the slots.

 

^ If you read some of the links I posted, there seem to be 3 scenarios for most owner's manuals:

1) recommends regular (the tC)
2) recommends premium (luxury brands)
3) requires premium (boosted, high compression)

Your brother sounds like he fits into the second one. And that's one time where it is OK to not run what is in the manual, but that's because of the word recommends. They recommend it for "Best" performance and running something else will usually be fine.

 

Wow, the Turkey Hill mini-marts in PA are Top Tier, who knew. And they have good ice cream.

 

There are NONE of them within 20 miles of me.

There's a Shell station to the south in Lawrenceville, but that's it.

 

You'll want to be careful with that. Avgas contains Lead, even though its LL(Low Lead) your catalytic converter may not like it.

 

I'm pretty sure he was joking...

Just throwing that out there incase your sarcasm detector is off.

 

I figured he could be joking, but then if he wasn't then whats the harm.