Normal fuel in a Catalytic corvette what to do....

[GiuG]

Hi guys quick question, I just picked up my Corvette 1975, from the mechanic, to "help" the carburator he put a full tank of normal gas into the car and not the unleaded one, is a trick he said. My version of corvette is one of the first catalytic, should I kill him or is a good choice? to come back to the green one, I need to wait the tank is fully empty right?

 

[Oneball]

Are you sure he put leaded petrol in and not just super?

Top the tank up with unleaded I doubt it’ll do anything to the efficiency of a 40 year old cat.

 

[GiuG]

I just want to know if the leaded fuel can harm the car that it suppose to be Catalytic, the mechanic said that the high octane help the carburator to start from cold, but I did not ask him to switch fuel... well there is a list of things that sounds weird, it was not a corvette expert ( classic car one ) how can I swap again fuel? I need wait until the tank is empty now? I can't mix the two types, right!! story short the the car now drives funny!!! Maybe I should one of you expert drive my car to understand what's happening

 

[Chuffer]

Hi guys quick question, I just picked up my Corvette 1975, from the mechanic, to "help" the carburator he put a full tank of normal gas into the car and not the unleaded one, is a trick he said. My version of corvette is one of the first catalytic, should I kill him or is a good choice? to come back to the green one, I need to wait the tank is fully empty right?

What is the so called `trick` meant to achieve ?
I would go with Oneball , a 40 year old Cat would be well past its best .

 

[Roscobbc]

Presuming in the meantime the exhaust (and converter) hasn't been changed for a new exhaust........being a classic you can dispense with the cat anyway!

 

[teamzr1]

If I recall correctly, Corvettes made after 1971 MY were designed to run on unleaded gas and your owner's manual may state :

"Your Corvette engine is designed to operate ONLY ON unleaded gasoline of at least 91 Research Octane.
The gasoline should have a Motor Octane of at least 83." Then it shows the following formula: R+M/2=87

If where you live do not do smog testing and no visual checking
I say dump those POS CATs, they were slobs, stole performance and caked up real easy and become bricks :-(

 

[GiuG]

If I recall correctly, Corvettes made after 1971 MY were designed to run on unleaded gas and your owner's manual may state :

"Your Corvette engine is designed to operate ONLY ON unleaded gasoline of at least 91 Research Octane.
The gasoline should have a Motor Octane of at least 83." Then it shows the following formula: R+M/2=87

If where you live do not do smog testing and no visual checking
I say dump those POS CATs, they were slobs, stole performance and caked up real easy and become bricks :-(

So the mechanic made a mistake, should I ask to empty my leaded tank then? or I just wait to use that fuel in time? As you mentioned, I'd like to drop the cat, but I live in a busy city, I'd like to be socially accepted for the noise, but you tempt me a lot .......they did a lot of mistake on my Vette and I need to fix them first.

 

[Roscobbc]

So the mechanic made a mistake, should I ask to empty my leaded tank then? or I just wait to use that fuel in time? As you mentioned, I'd like to drop the cat, but I live in a busy city, I'd like to be socially accepted for the noise, but you tempt me a lot .......they did a lot of mistake on my Vette and I need to fix them first.

Just use the fuel......it's very doubtful that it will cause problems......you seem to have more pressing issues.......

 

[teamzr1]

If worried, drive the car and dilute what gas is in the tank with unleaded

I would cut the CATs out and replace with pipe, will not change the sound that much and as it was those CATs are like bricks
and by now added more back pressure so replacing with pipe can only help engine breath, cleaner cylinder charge and a bit better performance

Besides those CATs are heavy so taking them off makes C3 lighter and haul ass better