What grade gas?

[Glue Maker]

I was just wondering what grade of gas people use. I always fill up on 93 (or was it 91? I don't read any more) Premium, and my dad always complains about me wasting money. IMO SHOs run like CRAP on anything less

 

[NotSoSlowSHO]

At $1.59 for premium...
I think Ill stick to regular for now

ONLY $1.39

regardless of price, my '89 SHO runs no different from grade to grade. So I feed it the 'cheap' stuff :thumbs_u:

 

[Glue Maker]

Hehe, 1.75 here. Does your gen SHO say "Premium Fuel Recommended"? On my dads 94 Cobra it just says 87 unleaded.

 

[PROPHET]

91 0ctane goes for $2.40 here.

 

[wuzzzer]

I know that on all Gen 2 & 3 they say 'Premium Fuel Recommended.' Not sure about Gen 1, but since the engine's the same as a Gen 2, I'd say they probably recommend it, too.

I go back and forth from low-mid-premium. Probably not the best for my car.
I can tell that with premium the car seems to have more power right at redline. With regular grade the power seems to drop off a couple hundred rpms lower than it does with premium.

 

[Mr Anonymous]

The conventional wisdom is to use the lowest octane gas that you can without causing knocking. That is what octane ratings are all about, anti-knock qualities.

The only drawback on cars like ours with knock sensors is that the PCM can retard the timing to stop knocking. Retarding the spark causes a richer air/fuel mixture, which can decrease fuel economy, increase emissions, cause the engine to run hotter, and reduce the longevity of both the engine itself and the catalytic converters.

 

[Glue Maker]

The conventional wisdom is to use the lowest octane gas that you can without causing knocking. That is what octane ratings are all about, anti-knock qualities.

The only drawback on cars like ours with knock sensors is that the PCM can retard the timing to stop knocking. Retarding the spark causes a richer air/fuel mixture, which can decrease fuel economy, increase emissions, cause the engine to run hotter, and reduce the longevity of both the engine itself and the catalytic converters.

There is a Ford technician in my car club and he says that this knocking is cause by the abnormally high head temperatures caused by low octane fuel. However, he also said that running it on low octane fuel can help reduce carbon deposits in the engine, but he also said it is nothing more than the occasional WOT can do

Higher octane gas runs cooler, and IS more explosive (Don't listen to EPA.gov!). I don't remember the exact numbers, but I can almost for sure say that my SHO gets better performance and economy running premium.

My SHO will knock with 87, because my dad filled it up that time It sounded like it would throw a rod or something under a load.

 

[2 4shofast]

Try paying $5.20 a gallon for 90 octane......its not fun paying over $75.00 to fill up

 

[Glue Maker]

:jaw Drop:

 

[stephen newberg]

Yes, gas prices in the US tend to give a rather distorted view as per the rest of the world. Or the rest except the Arab producing nations, anyway. I think a US gallon is running about $2.30 US dollars in Nova Scotia at the moment, if I did all those conversions right.

The regular or premium question has come and gone lots of times. If you look over on V8SHO.com I am sure you can find long threads that deal with it, some in great detail. What it seems to come down to is that for a Gen III the sensor system, if working correctly, is so good that you should never get knocking, so using regular is just fine, though many people have noted that they seem to get better gas milage figures from premium. If it is enough better to offset the cost difference varies with location and price.

pax, smn

 

[99V8SHO]

Up until a few days ago I only filled with premium. Then a topic started on the V8 mailing list about what grade gas people use. The consensus was the pretty much everyone ran just fine with regular. No performance lost, some even saw better fuel economy. I just recently filled my tank with regular and have noticed absolutely ZERO change in terms of performance. My fuel economy so far seems to be unchanged but I will see what mileage I am at next time I need to fill up.
Premium here is up around $2.05, and regular is hovering around $1.80.

 

[TVSHO]

Gas is cheap where I live compared to the rest of the nation. I paid $1.72 for 93 octane today.

In contrast I travel to Germany frequently and have spent $60/day for 4 days in a row due to high prices and high consumption...thanks to lots of triple digit driving!

...and in the 8 years I owned my SHO, it ran the exactly the same on either 87, 89 or 93 octane.

 

[SHOZ123]

Higher octane gas runs cooler, and IS more explosive (Don't listen to EPA.gov!). I don't remember the exact numbers, but I can almost for sure say that my SHO gets better performance and economy running premium.

Actualy higher octane gas contains fewer BTUs of heat per gallon and is more resitant to ignition. The additives used to inhibit combustion take the place of hydrogen you would be normally be burning. This is why it burns cooler, just like adding exhaust gas via an EGR valve.

Hard to say whether you really get better perfromance on premium unless you can monitor the ignition timing in real time. Some areas have very poor gas and this will neccesitate the use premium. :corn: