Premium gas in old cars?

I've been putting premium in my impalas. It's about $6 more per 20 gallons. I have this idea in my head that it will keep my carb and fuel system cleaner, therefore keeping down maintenance for one. Also my 96 civic vtech runs obviously better on premium than regular, so I'm extrapolating that to the chevy 350. I can't say it's an obvious difference in my impalas though, although I think the impalas run stronger and smoother on premium. I don't mind if i'm wasting a little money putting premium in the mid 1970s chevy's, as long as it's good for the driving experience and lower maintenance. What do you think? Oh, also, gas sucks these days so I'm just trying to help the poor old impalas out.

 

I found really no differance between regular and premium in the Crewzer so I stick to regular. My old truck did'nt seem to like premium, so again I stick to regular and it clearly runs better..go figure.
As winter was coming and frosty mornings happened I started dumping methal hydrate in each tank after fill up, about a litre to tank full and I swear both motors run better. I think I will keep doing this fore ever.

 

Now that I'm running 10:1 compression, I don't have much choice but fill with premium.

 

Some cars.....Mustangs for example, hate the good gas.....some run rich on it......I run regular 87, from shell, and once a month run a tank of the expensive stuff.....you really want to clean it out, once a month throw 5 gallons of race fuel through the thing lol

 

Premium gas is all hype. Unless the owners books says to run it, dont.

 

I agree with F27. UNLESS it is a built engine. Do what the engineers tell you about your specific engine.

 

I run premium in my goon,help with the knocking and trust me I need all of the 60 hp out the goon...

 

I found this on another forum:"I run 93 because of compression and cam timing, but you want to be careful and not burn too high of an octane for your motor. The higher the octane, the higher the flashpoint, and therefor the higher the temp needed to ignite it. In a stock motor that was not designed with high compression, overly advanced timing, etc. you may actually loose mileage and cause carbon buildup due to the fact that the fueld does not combust completely. As long as your motor does not "ping" under load when properly tuned (poor ignition and/or fuel delivery can also cause similar problems) and does not show signs of "dieseling" when shut off, you should be fine running 87-89. Also most premium fuels run extra detergents, if your motor does not combust all the fuel properly, the detergents also get left behind with the carbon and can cause more trouble. Whatever you run, buy your gas from a station that does alot of business (less chance of getting gas with sediments or condesation accumulation such as at a Mom&Pop's station). Nomatter where you get your gas, putting a SMALL bottle of carb/fuel injection cleaner once or twice a year is not a bad idea (no need to overdue it especially with todays more effecient engines)."

I'm going to try regular next and really pay attention to how the impalas run.

 

Carbon on top of pistons will cause dieseling and spark knock. If you think you might have build up, run a can of Seafoam through a vacuum line (not the advance line). Just do it outside and not in the garage.

 

My 455 has 8.5 to 1 compression and runs fine on 87 until I'm in the mountains with the trailer on back. Then it needs premium or it pings which is not a good thing.

I have read many articles over the years that all stated if your car has lower compression and is tuned properly it will run just fine on 87 and you are not gaining anything with premium. If your engine pings the recommendation has been to check the timing to make sure it is set properly, and if it is, then go up to the next octane rating and see if that stops the ping. If it does, stay there.

As for Datsun411's high horse power wagon with a roaring 60 horse power it must be a real terror ripping the roads. I guess mine is sad in comparison as I only have 49 horse power (per cylinder of course ). It barely pulls itself down the highway

Saf57

 

Usually if a car has 10.00 or above compression ratio if will need Premium. Check the owners manual and work with that.. My 72 500 inch cadillac engine in the Pacer wagon requires Premium at 9.0 compression ratio according to the owners manual and TSM but I run 87 octane w/o any problems due to the lighter weight body I guess.. never pings or diesels..

 

At least here in Caklifornia where the Eco-Nazis live and breath, we were the first state to ban leaded gas for cars. Secretly this back door deal was actually an effort to get old cars off the roads of the state. See the object was to get the old cars to be fueled by UNleaded gas, with the hopes that since unleaded fuel burns at a higher tempreture eventually it would ruin the valves and rings of these older cars. California made the replacement parts for these old cars so exorbantly expensive only the rich would be able to afford to fix them. To run on leaded gas you need to put harden seat valves into the cars motor. Older cars meaning the ones that originally ran on Leaded gas, cars without catolitic converters. The powers that be had some pipe dream back in the early 1990s that they wanted us all to be driving brand new Hondas and would squeeze us into them. It failed.

So many people with collector cars stood up and yelled that this extra cost was at first denied then dropped. I remember the massive demonstration on the capitol in Sacramento protesting the new unleaded gas force fed us. Back then I had a 1974 Chevrolet Vega. I remember getting busted since I refused to move it from the capitol lawn , plus it peed power steering fluid and oil on the grass.

Today I have a 1972 Dodge and its not been touched or molested. Its as it was when it rolled off the factory. Originally it ran on leaded gas but I run regular unleaded in it, only because the motor has been redone. The harden seat valves have been installed. No danger of burning the valves up. My 1965 Mercury Parklane however has not been redone, so eventually it will need some serious motor work. Thanks to our Eco-Nazis

 

Apparently this is more of a myth than anything.

From one of Jim Hand's Pontiac performance articles:

 

While I'm not sure about other engines, I do know that Ford saw fit to change over to hardened seats in the 200 I6 sometime in the seventies.

I'm sure all the manufacturers switched around the same time so there must've been a good reason other than myth?

 

Myth was probably the wrong word. Exaggeration would have been better.
Clearly, the hardened material is a better choice for the application, so it would be logical to upgrade the designs once leaded fuel was no longer available.
The potiential for damage seems to be exaggerated as part of the push to move the public towards new, more fuel efficient, lower emission cars.