I am ... but I saw this article on 12 things you should stop buying and one was premium gas ... unless you own a Ferrari:

http://moneyland.time.com/2011/08/19...mium-gasoline/



I request your opinion as it would be great to buy the lesser grades if it would not be detrimental to my near-pristine (56K miles) 1993 SC400 motor.

 

I have a 92sc400 and I tried a lower octane fuel once.The motor reacted badly....pings,no get up and go.For the 20 cents extra per gallon the premium is worth it.Nice sc ,BTW.

 

yup...

 

Good to know ... thank you.

 

Mid grade is more than enough, No need for 93.

 

Enjoy the carbon deposits in your motor, and wondering why you have no power.

You'll get LESS hp on an already sub-par 200"ish" WHP N/A version of a 2JZ, and then you'll have to push the gas even further to accomplish the same acceleration you naturally accelerate at every time.

If your car calls for premium, it's because the ignition timing,etc has been optimized for it. If it doesn't, you're wasting your money throwing 93 in it.

I would love to see someone come to LA/TX in this heat and try to run 87 in an SC300 and see how fast it detonates at stock ignition timing.

 

on my 1995 sc400 i only use 93 octane, but i just bought a 97 sc400 and the guy told me he puts in 93 octane every 2 tanks otherwise he uses the cheap one. call me crazy but my 95 has way better throttle response and is way faster and thats that the 97 is supposed to have like 10 more HP. i think its the gas so im waiting till i run out all the way to put the better gas in it to see if it runs better... DONT USE CHEAP GAS...lol

 

Yea I only run 93, & I tried to run mid grade back when 93 was $4.22 a gal. Didnt have good results, especially with the SRT chip leaning it out.

 

About gas, does anyone go to specific gas stations? For example, I only go to shell for my turbo SC, but tried putting another unknown brand and car started knocking and had problems starting until i used Lucas octane booster. Although, it was tuned with shell 93 v-power.

To add on to the topic:
would it benefit getting 93 from shell or chevron with their special additives on a stock motor or any 93 rated gas will do?
What is everyone's input on this?

 

shell 89 for me: http://www.fuelly.com/driver/jadu/sc300

 

On N/A cars (especially older, low compression designs) there is no discernible difference between high vs low octane. If an ECU doesn't detect enough knock to pull timing, there will be NO effect on power.

In modern high compression motors it can and DOES make a difference (I personally spent some time back in 2009 in a pre-production Corvette ZR1 that was being low octane tested) Many ECU's will pull significant timing in response to knock.

That being said, on my stock NA 2JZ I ran both. No difference that I noticed. My motor didn't blow up. Passing power was not affected. Ran nearly 220,000 miles without problems before the motor got swapped.

On my 1JZ? I'll only run premium

 

91 for me always... I've been using Chevron gas for years and I've had good luck. I also use the Techron fuel system cleaner twice a year... Techron is the **** man. But if I'm poor, I will get a few gallons of 89 ^^

 

Anything over 89 is a waste of money as the compression and timing are aggressive enough to warrant anything more but we are talking pre vvti here.

 

So this topic comes up again....i will always use premium 91+ (93 for me) as the owners manual recommends and warns otherwise.

 

The SC400 has a high compression engine. It should be run on high octane gas.
Iv'e been using 93 octane BP gas in my 99 SC400 and my 2001 solara V6. The Solara has 200,700 miles on it and I still have to look at the tach to see if the engine is running. Feed it good and it will run good, feed it crap and it will run like crap.
I tried cheap gas for a few tank fulls, performance and milage both suffered.
There really wasn't any savings.