I have a few issues with the comments in the article

First is the use of premium when the owners manual calls for its use. I have used middle grade / regular in both my Murano and Vette. The dollar differance between grades is < 10%. When I use regular or middle grade my gas mileage drops > 10%.

Here in Texas, when it is summer and temps are > 100, it is a fact that you get less gas. This has been proven here several times not only on new shows but also the State Bureau of W & M backs it up.

 

If you want to believe news shows, then you should check out this clip, from one of our local stations: Miracle System
Please let us all know how it works. HPH

 

That sounds almost as promising as the aforementioned miraculous Tornado.

 

Those "Brown's gas" generators have been around a long time. Like all this stuff, every time the public starts getting worried about fuel prices they pop up onto the radar.

If they do anything, it's probably just that they lean out the fuel/air ratio a bit.

 

I was going to say that at highway speeds and partial throttle the blower probably had no effect one way or the other. Then I remembered it was you driving.

 

Not to mention leaning out one's wallet in the process.

 

I have read that if you have a Berk high flow cat, that it does improve gas milage. Can anyone confirm this.......Uhhh Dean comes to mind
i think he has one. This may be my next purchase.

 

be VERY careful when installing these gas saving devices.
for example your already getting a 60% improvement with the tornado.
if you get another 45% with other devices you'll soon have 105% saving meaning an extra 5% gas.
pretty soon your tank will be overflowing with the %5 excess gas.
this can cause a severe fire hazard, so be careful....

 

Overly hot chili can sometimes have the same effect.

 

... and it became a discussion on radar detectors. I'm not sure people were really focused on saving gas there.

It seems to me Consumer Reports doesn't understand the difference between cars designed to take regular and cars designed to take premium. That's not surprising, since they probably consider all performance cars a waste of money.

It's true that cars designed to take regular benefit little from premium. There isn't much room to increase the compression ratio by advancing the spark timing, so the gasoline just burns the same, and the energy content of regular and premium is nearly identical. (The exception would be really old cars with a lot of cylinder deposits built up - I have a friend who once had a twenty year old 1964.5 Mustang and he saved a lot of gas with premium because using premium meant he didn't have to warm up the engine for five minutes before driving. That's an unusual case, though.)

For cars designed to take premium, though, it's a little different. Even a modern engine designed to take premium has a higher compression ratio than one designed for regular; run on regular, the spark gets delayed to reduce the effective compression ratio. That also means you get less work out of each cylinder full of air/fuel mixture, though; if the power stroke normally moves through, say, 160 degrees, and the spark ignition is delayed by 5 degrees on regular, then you're only getting power through 155 degrees - you're losing 3% of your power. To make up for that, you'll push down more on the accelerator, resulting more fuel use.

The S2000 also has a limited ability to delay spark ignition - I think that's why my owner's manual strongly recommends premium, and I think it says even the minimum octane requirements to avoid engine damage are still higher than the 87 for regular.

Given premium in my area only costs about 3% more than the 89 octane intermediate grade, I don't think there's any point to using anything other than premium in an S2000.