# Correct Oil Fill Quantity



## gnsjoy (Apr 29, 2014)

66 with WS engine. Owners manual says 7 quarts with filter change. Dipstick says 5 qts (can not verify dipstick is the correct one). Pontiac Shop Manual say six qts. Which is correct?


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## Bill E (Apr 14, 2011)

As far as I know, most of the pontiacs from the “muscle car” era take 6 qts. My 68 GTO takes 6. I would fill it slowly and keep checking the stick. I don’t know if an oversized oil pan was an option on any of them.


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## GTOJUNIOR (Aug 7, 2011)

AMA Spec sheets show 6 (less Filter refill), so 7 with new full filter.
Your dipstick in not correct.


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## PontiacJim (Dec 29, 2012)

gnsjoy said:


> 66 with WS engine. Owners manual says 7 quarts with filter change. Dipstick says 5 qts (can not verify dipstick is the correct one). Pontiac Shop Manual say six qts. Which is correct?


Interesting. My '68 manual states 5 quarts in the pan Plus 1 quart in the filter for a total of 6 quarts. My 1966 AMA 389 engine spec says 5 quarts -pan, plus filter which is 1 quart for a total of 6 quarts. Chilton states 5 quarts plus 1 for the filter for a total of 6 quarts.

All the V8 Pontiac cars I had used 5 quarts plus 1 in the filter for 6 quarts.

Here is another thread on the same question- https://www.gtoforum.com/f50/oil-type-capacity-20669/


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## GTOJUNIOR (Aug 7, 2011)

:surprise:Amazing how convoluted all these manuals/books are. 

1966 AMA TEMP/LEM 6+ 
1966 AMA GTO 6+
1966 FACTORY SERVICE 5+
1966 MOTORS 5+

I think its safe to go with the consensus of 6


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## PontiacJim (Dec 29, 2012)

GTOJUNIOR said:


> :surprise:Amazing how convoluted all these manuals/books are.
> 
> 1966 AMA TEMP/LEM 6+
> 1966 AMA GTO 6+
> ...


Interesting.

I do not have the AMA Spec for year 1965, but, my AMA Spec dated 9-2-65 for year 1966 GTO clearly shows 5 quarts plus filter where your states 6 quarts plus filter.

Looking at the 1964 AMA Spec for the Lemans/GTO Option, it also states 5 quarts plus filter.

The 421 Super Duty used a 6 quart pan plus filter.

I have seen this in the specs on the Plymouth Fury. Sometimes they will use the previous year specs on a current engine/car that is still in production. Even options are listed for the new up and coming year and never made available. I suppose that the car specs may have to be submitted at a certain time frame to the AMA and to meet these time frames, they may use some previous engine data to fill in the blanks for the current model engine.

I can also see someone not paying attention when they write the specs and did not notice or understand the fine print "less filter - refill (qt.)"


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## GTOJUNIOR (Aug 7, 2011)

The AMA sheets I've shown above are the 9-2-65 for 1966 pages.


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## PontiacJim (Dec 29, 2012)

GTOJUNIOR said:


> The AMA sheets I've shown above are the 9-2-65 for 1966 pages.


Yep, and why I said "interesting, my AMA 9-2-65 for 1966 page shows 5 quarts."


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## geeteeohguy (Feb 2, 2008)

The pan got changed around 1968-69 to a lower capacity. (Has a drain plug on the side instead of at the rear). My '65 389 holds 6 quarts loaded for bear, and my '67 GTO with it's original engine, pan, and dipstick holds 7 quarts. Always has.


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## PontiacJim (Dec 29, 2012)

geeteeohguy said:


> The pan got changed around 1968-69 to a lower capacity. (Has a drain plug on the side instead of at the rear). My '65 389 holds 6 quarts loaded for bear, and my '67 GTO with it's original engine, pan, and dipstick holds 7 quarts. Always has.


Interesting. The 1967 AMA specs do indeed state 6 quarts plus filter. Looked at the 1968 AMA specs and it goes back to 5 quarts plus filter.

Is the '67 pan unique or are the AMA specs unreliable? My Factory Service Manual for 1968 also states 5 quarts plus filter.


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## geeteeohguy (Feb 2, 2008)

The owners manual says 7 quarts capacity for the '67. Pan looks identical to my '65's pan...but I never measured the capacity off-car. The 389 in my '65 is a non-messed-with engine I bought off a buddy for $150 in 1980. It was the original engine in his '65 GTO, and my rebuild was it's first....so the oil pan, dipstick, windage tray are all oem. It holds 6 quarts with the short filter, 6.5 with the long filter. The 400 in my '67 is original to the car and had never been opened until I overhauled it in 1988. Same story---all original parts, and a 7 quart engine. My best friend's '67 back in the day was also all original and was a 7 quart engine. I've never had a '66 with the original engine, so can't comment. If I remember, though, all of my '66 GTO's had 6 quart capacites, total. In '68, everything changed. I have never owned anything newer than a '67.


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