There was an article in the August issue of Corvette Fever where they tried out this additive in several cars (including C5) and found an improvement in acceleration and mpg due to the improved combustibility features.

I am always skeptical about additives but decided to give this a try in my 95 LT-1 (about 70,000 miles on the odometer). It may be my imagination but the car seems to be stronger from a start and more responsive overall. This is not based on scientific measurement but just my butt-o-meter.

Has anyone else tried this stuff?

Doug

 

There's no liquid in the world that will make any car faster if the car is operating at 100% capacity. Certain substances will allow the car to operate and function as it was designed. I haven't use this PurEscape, but if you're feeling more power, then it probably blasted away some carbon or crud in the lines that enabled your car to run as it was designed.

 

Found a link to the site for Chevron's Purescape:

http://www.chevron.com/products/purescape/about/

It is actually a catalyst ... So in this case, this is one additive that could possibly work as advertised. What were the amounts of improvement that Corvette Fever measured?

 

There's no liquid in the world that will make any car faster if the car is operating at 100% capacity. Certain substances will allow the car to operate and function as it was designed. I haven't use this PurEscape, but if you're feeling more power, then it probably blasted away some carbon or crud in the lines that enabled your car to run as it was designed

Different gasolines with different octane levels give different results?

 

Higher octane fuels only help higher compression engines. A low compression engine will not benefit from running a high octane fuel.

Here's a link about octane and here's an excerpt from the link...

The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites. When gas ignites by compression rather than because of the spark from the spark plug, it causes knocking in the engine. Knocking can damage an engine, so it is not something you want to have happening. Lower-octane gas (like "regular" 87-octane gasoline) can handle the least amount of compression before igniting.

The compression ratio of your engine determines the octane rating of the gas you must use in the car. One way to increase the horsepower of an engine of a given displacement is to increase its compression ratio. So a "high-performance engine" has a higher compression ratio and requires higher-octane fuel. The advantage of a high compression ratio is that it gives your engine a higher horsepower rating for a given engine weight -- that is what makes the engine "high performance." The disadvantage is that the gasoline for your engine costs more.

 

I do not have the issue in front of me but the only thing they measured was g-forces on straight ahead acceleration. I believe on regular premium gas the numbers were on the order of 0.62g. After adding the PurEscape they got something like 0.69g. Straight 100 octane gas was slightly more than 0.7g, and adding the PurEscape to that did not make much of a difference.

 

That's ridiculous. Besides, wouldn't a normal corvette lose a lot of power running 100 octane?

 

I'm not a chemical engineer but the only real-life experience I can attest to was a few years ago when I tried using a few gallons of 100+ octane "race fuel" that my local Union 76 station sells (the premium stuff in SoCal these days is typically 91 octane). I added enough of the 100 to bring the overall octane up a few points (maybe to 93 or 94 octane) and definitely felt a difference. I never tried running on straight 100 octane.

 

Purchased 100 octane in California (Pasadena Union76) and in Arizona at a Mobil station, with out a doubt noticed immediate results. More power and appeared the response improved. I put a full tank just prior to my scheduled California Emissions Test, burnt off half of that and passed the test with flying colors(probably would have passed regardless). One station in Torrance stated he had never seen a Corvette with readings this good.
Now I really do not purchase it as much, although once every three month I will put 10 gallons in the car.

My .02 worth

Before there was a Union 76 they were Pure Gas Stations

 

More power, better response, and cleaner emissions - those are pretty bold claims for a motor that is designed for 87 octane.

I mean... 100 octane has less energy, so the only way it could improve power is if the motor was previously knocking and therefore increased the timing. Wouldn't it also burn less thoroughly, which should increase emissions?

I don't know, I'm highly sceptical to say the least .

 

I guess the LT-1 engine will run on 87 octane but I do not know if that is ideal or what was intended. I thought that these were made to run best on premium grade?

 

He drives an L-98 and the manual says to use 87.

 

Getting back to the original question--has anyone else tried this stuff? Again, I do not believe it is an octane increaser but, rather, alters the combustion. In the Corvette Fever article, they supposedly tried this stuff in a variety of cars ranging from import 4-bangers to the C-5 and there were generally improvements (at least in their acceleration "g" measurements).

 

My '90 said use "Premium Only" it is okay to be highly skeptical........

 

I googled and found a few other auto forum sites talking about this stuff. I also found that there is a printable rebate form for $5 back from Chevron for trying this (costs about $6 or $7). I am naturally curious so was willing to try this without the rebate and was still impressed that it seemed to do something. I guess if you are more of a skeptic you would only end up losing a couple of bucks by trying. I should also have mentioned that I did not add the entire bottle to the tank but wanted to see if I could tell the difference from adding 1/2 bottle.

Anyway, I don't own stock in Chevron or have any other financial interest, and don't care to get into endless debates over the benefits or detriments of fuel additives. I was just passing along my experience with trying the product.

 

On my '88 when you open the fuel filler lid it is printed "Premium recommended"

Here is the link to the actual product and the link for the printable rebate coupon.

http://www.chevron.com/products/purescape/default.asp

 

So far ... and understandably ... a bunch of knee jerk reactions to this as if it was a typical fraudulant octane booster.

So why is everyone talking about octane??? There is absolutely no claim that this increases octane. And you can see fron the graphs that it doesn't increase octane. If you look at the combustion pressure graph on the website, you can see that more fuel is burned earlier in the cycle, and as such, less is wasted. The before and after curves look just like a low compression engine's graph compared to a more efficient high compression engine's graph.

I'd bet money that a controlled dyno comparison would show an improvement on a typical NA engine. Now on a supercharged or Nitrous engine, you probably would not want the higher pressure peak.

Edit: I just did a search and found this article: http://www.innovatemotorsports.com/resources/hrp1.pdf

The improvement from the Rocketfuel 100 octane gas was probably due to the higher specific energy content of the fuel, not due to the octane rating.

 

I found an updated printable rebate coupon.
Chevron PurEscape - $5.99
Purchase Chevron PurEscape Performance Optimizer and receive $5.99 back by mail. Offer valid 8/1/07 through 8/31/07.
Limit 2 per customer.
http://www.oreillyauto.com/EW3/GetUp...whatsNew14.pdf

Don't know if the rebate is specific to purchasing only at O'Reilly auto parts or not.

 

I someone in the Raleigh/Durham area of NC wants to try some, I'll offer up some free pulls on the dyno where I work to lay this one to rest. Bring your car in, we'll strap it and make 3 pulls with it hot; just like it came in off the street. Add the mojo, unstrap, take the car to lunch to give the mojo every opportunity to mix and get cross-mojinated in the tank. Then, we'll strap it back down and see if it really does make more power.

I'm pretty skeptical, but who knows.

As far as 100 octane helping a stock C4, I've seen probably 50 or 60 stock or near stock cars try 100 octane on the dyno. Every one of them made less power than good ole' 93. And every time the owner swore the car was faster, had better throttle response, etc... The only time you'll make more power with 100 octane is if you bump the timing, add boost, or do something else to take advantage of the higher octane.

If there is a mechanical issue with your car that is causing knock retard, like an especially carbon'd up piston or something, then the 100 octane might help you get your full timing advance back, but that's really the only scenario where 100 octane would help make more power on a stockish car.

My .02.

 

I'd be very interested in your data when someone actually brings their car into your shop and tries the stuff.