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Cadillac 0 - 60 Times: 1949 - 1969

Started by Eric DeVirgilis CLC# 8621, May 23, 2023, 03:39:09 PM

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Scott Nellis

   Thanks so much Eric for the original post and all the added information. Very interesting and impressive results for such large, heavy cars.
1957 Eureka Hearse
1965 Miller-Meteor Hearse
1968 Miller-Meteor Hearse
1968 Fleetwood Brougham
1970 Superior Hearse

dochawk

Quote from: Eric DeVirgilis CLC# 8621 on May 25, 2023, 12:15:28 PMThe 12.4s & 13.3s timings for premium and regular fuel were reported by Popular Mechanics whose analysis and results were much more exhaustive which was also the only article to publish figures for two fuel grades.

that difference was what stuck out tome.

I wonder how they did that?   Did they adjust the timing between the two, or did they back off the accelerator on regular, or . . . ?

Or was there more difference in the grades at the time than just octane and more cleaners?

I do recall an article when the northstara Wass brand new that said something to the effect that Cadillac had been telling owners for years that they didn't need to use premium, yet found 90% were using it anyway.  So they tuned the Northstar to take advantage of it, but with advanced knock detection to back off on the timing if someone used regular.

I found my '97 ETC was quite happy on regular, even though it said to use premium (while my '06 Miata was very much *not* happy when I opened the throttle in an emergency after absent-mindedly putting regular in the tank.  I found that it was happy on mid grade, though).
1972 Eldorado convertible,  1997 Eldorado ETC (now awaiting parts swap from '95 donor), 1993 Fleetwood but no 1926 (yet)

Eric DeVirgilis CLC# 8621

#22
Quote from: dochawk on May 27, 2023, 08:38:14 PMthat difference was what stuck out tome.

I wonder how they did that?   Did they adjust the timing between the two, or did they back off the accelerator on regular, or . . . ?

Or was there more difference in the grades at the time than just octane and more cleaners?

I do recall an article when the northstara Wass brand new that said something to the effect that Cadillac had been telling owners for years that they didn't need to use premium, yet found 90% were using it anyway.  So they tuned the Northstar to take advantage of it, but with advanced knock detection to back off on the timing if someone used regular.

I found my '97 ETC was quite happy on regular, even though it said to use premium (while my '06 Miata was very much *not* happy when I opened the throttle in an emergency after absent-mindedly putting regular in the tank.  I found that it was happy on mid grade, though).


I can only report what was published. I have no idea what methodology evaluators used at the time.

All V8 Cadillac engines required premium from 1990 - 1999. Beginning in 2000, premium was no longer required for the reasons you mentioned however the manual stated that performance and fuel economy would be improved by the use of premium.

I've never used regular whenever a car had "premium fuel only" labeling but once when I drove a friend's 1992 Eldorado with the 4.9 (not Northstar), the engine was pinging horribly. Knowing what a cheapskate this guy was, I knew in an instant what he did and he immediately folded under questioning. Never again did he use regular in the car.
A Cadillac Motorcar is a Possession for which there is no Acceptable Substitute

V63

#23
I never understood of buying  into performance with both feet  ...but then refuse to pay for the recommended  premium fuel.

 It's more common than you might think.


Dave CLC#16900

When I worked on the 92.5 Northstar Allante', I believe we did a spark table for up to 100 octane (it might be a slightly lower number) in an effort to achieve 300 hp.  We only certified for 295 hp.  The knock sensor looks for knock.  If detected, goes to a lower octane table.  If still detected, goes to a lower table, etc.  When you put in good gas, the opposite is true.  We also added a couple of degrees of spark advance when cruise control is enabled to improve the mileage.
Dave CLC#16900

1956 C 6237SDX ELS
1975 C 6CD47 CDV