progood

I was using 87 octane unleaded and putting in a lead additive from the local automotive store. Then I was told my stock '73 Olds Delta 88 455 Rocket was manufactured to run on unleaded (is this true?). I was skeptical but started running on 89 octane unleaded with 10% ethanol with no additive for a while. Any suggestions on what I should be running? ...and what are side affects of not using the correct fuel?

daves62

I believe by 1973 gm had made it so all of their cars could run on lower octane fuel preparing for the catalytic converter.

Hurstolds1973

I think they were to run on low octane also, but it should be listed in the glove box on the 73's. If it runs properly then why run higher octane unless you gotta a heavy foot?

citcapp

Runs on regular. If premium would have been required it would be noted on the dash or the lid of the gas filler

88 coupe

That is what it was designed to use.

Dollar for dollar, beer would have given you a far higher return on your "investment".

Higher "octane" than it was designed to use? See my second comment.

Norm

progood

Thanks all for the input - sounds like I'm ok with what I'm doing. Mybe I'll splurge and try out premium to see if I notice the difference.

jeffreyalman

sorry if old but I was searching for ethanol threads and this came up. I was looking at oldcarbrouchures.com last week and read the entire brochure on 72 Cadillacs, and they mentioned how their engines were designed to run on low and no-lead gas

Summerof84

The sticker in my '73 Cutlass says 91 octane and no lead fuel.

clinton70

Sorry to bump but what about a 72 Toronado 455 Rocket?

Guy I bought it from said put 89 in it, not sure if 87 would do as well?

Summerof84

You could probably retard the timing and run 87, but my Mom's '73 Toro 455 pinged like crazy at the factory timing settings on 87. She ran the 91, I enjoyed the extra Varoom!

jeffreyalman

my Toronado pings on everything, my 88 runs better on 87 than 93, everyone gets 87 and we are 10% ethanol in Fla it sucks

442much

In the caravan to Lansing for the 100th anniversary, cars that filled up in Nebraska started pinging untill the next fill up, me included. I think the gas there had ethanol in it too.

jeffreyalman

well Ken my Toronado was there too do you remember if it pinged? It seems to have pinged since I got it, and that was before ethanol started.

I seem to recall that the 455s at least the smogged ones, tended to ping.

That said, I drive the wagon every day, use 87 with ethanol, same year as the Toronado, also a 455, and NEVER a sound out of it!

Texas Jim

So, what is the break-down f/ the different years? I ran my '71 455 on what the stations call 93 octane, and usually used Shell. I had no pinging at all, w/ Shell or 7-11. So come on you "Olds Masters," give us the run-down as to what years and what gas to use after '70, when the engines went low compression. Thanks in advance.

Destructor

I use 89 in my 70 Cutlass 350, I once accidentally put 87 in and it ran fine if I was gentle on the gas. I occasionally mix with 91 if it is a very hot day and/or I intend to thrash it a bit. I also add MMM to the gas. I had a 71 Caddy which required at least half the gas to be 91. Both my Caddy and Olds engines I beleive are the same compression ratio.

joe_padavano

All Olds engines have been designed to run on low-lead or no-lead regular since the 1971 model year. Carbon buildup or non-stock ignition timing can cause pinging, but if the engine is clean and stock, then unleaded regular is fine. In fact, for the best mileage and performance, you want to burn the LOWEST octane gas you can without pinging. Higher octane allows other engine mods that can increase performance even further, but for a given engine, use the lowest octane you can get away with.

jeffreyalman

Joe is there any truth to the myth that my era 455 had a propensity to ping or am I imaging that? And why not the wagon, just the Toronado?

AlanT

my recent experience. the .P.O told me He used reg. I put gas in for the 1st time and thought I might treat her to some premium! SHE dont like it!
Hesitates, and feels like i have no vac advance. took a quick look under the hood incase anything got disconnected and its sweet as it looked in 1972 as it should at 55k!

oldcutlass

If it were tuned to run with the higher octane it would like it better. The higher octane allows you to run more advance in your timing with no pinging.

AlanT

I was happy with it bfr. it didn't ping AT ALL! Also no knock when re-starting hot!

somethings are best left unfked or if it aint broke dont fix it LOL!