Emissions and fuel octane

ensure the car is fully warmed up first, by taking it for a good run out.

I don't think 98 will make any difference, assuming the carbs are set for that.

 

The only thing that dictates required octane level for a naturally aspirated engine is compression ratio. Assuming your car hasn't had its compression ratio altered (highly unlikely), increasing the octane level beyond what is normally required will do absolutely nothing.

-mick

 

Rob the gentleman , two posters, gave you good advice. Most of the state tests only require the exhaust pollution is as required the year the car left the factory. It makes sense you cannot expect a 1953 Corvette to ever have the same exhaust as a new Corvette. So with good plugs and tune up you should be okay.

Some of the cars that do not have a vin number and are manufactured by a MDO or manufacturing direct order are different. Cars like the Arial Atom. In that case call the manufacturer and they will help you.

Do not worry things will work out

Best

Lee

 

one advantage Super (97/98) gives you over normal (95) is the octane rating stays higher, if you leave petrol in the tank for a while, so whilst both degrade with time, the 98 is starting in a higher place.

 

Personally I just use Stabil in my gas. You can buy it at any car parts store. Modern gas only lasts for 3 months after the gas leaves the refinery than it starts to turn to varnish and than it becomes gelled. This is for any octane of fuel.

I have used Stabil in all of my cars for over two decades and it has worked well. I have no affiliation with the company only a customer. At one point I owned 16 cars and some did not get driven very much some as little as 100 miles a year.

The poster may be right I just never heard it before. I have heard that marine gas stays a viable gas longer.That makes sense to me but I really do not know and it is more expensive than car gas.

Best

Lee