Eldorado 1968
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The motor oil would have been 10W-30 or 10W-40 API SD. The ATF would have been the original Dexron.
Of course, neither of these are available now. Any conventional SM/SN 10W-30 should work. If you're concerned about flat tappets, you could always add a little ZDDP.
Dexron III is backwards compatible with Dexron.
Of course, neither of these are available now. Any conventional SM/SN 10W-30 should work. If you're concerned about flat tappets, you could always add a little ZDDP.
Dexron III is backwards compatible with Dexron.
10w30 or 15w40 HDEO is the general recommendation around here for older cars like this with flat tappet V8s.
15w-40 HDEO for sure. Dex/Merc for trans.
15w-40 HDEO and Dex III are what I use in my '62 Buick. The old Type-A just never seems to be in stock. 
Why does everybody assume that these engines are "flat tappet" I don't get it? Standard hydraulic lifters just like every other GM product in that time and era. No, am I wrong? How bout some documentation. I have an old Motor Manual,I'll check. Well, it only covers back to 1969, but if memory serves me right the 472 was the engine of the day in caddy's in 68, so standard hydraulic lifters. Why all the fuss about special oil for these engines?
Originally Posted By: Scotty59
Why does everybody assume that these engines are "flat tappet" I don't get it? Standard hydraulic lifters just like every other GM product in that time and era. No, am I wrong? How bout some documentation. I have an old Motor Manual,I'll check. Well, it only covers back to 1969, but if memory serves me right the 472 was the engine of the day in caddy's in 68, so standard hydraulic lifters. Why all the fuss about special oil for these engines?
In this context "flat" means flat-bottomed (non-roller), not solid (non-hydraulic). Modern oils have reduced anti-wear agents to accomodate catalytic converters, which is OK with roller cams but destructive to non-roller ones.
Why does everybody assume that these engines are "flat tappet" I don't get it? Standard hydraulic lifters just like every other GM product in that time and era. No, am I wrong? How bout some documentation. I have an old Motor Manual,I'll check. Well, it only covers back to 1969, but if memory serves me right the 472 was the engine of the day in caddy's in 68, so standard hydraulic lifters. Why all the fuss about special oil for these engines?
In this context "flat" means flat-bottomed (non-roller), not solid (non-hydraulic). Modern oils have reduced anti-wear agents to accomodate catalytic converters, which is OK with roller cams but destructive to non-roller ones.
So how is that different than many modern engines with overhead cams? Just had a vg nissan engine apart for a wiped cam lobe and the lifters are much like the flat tappet lifters yet hydraulic by design. So why do these old engines require special oils? Don't modern oils carry sufficient properties to lube these?
Much higher loading is the reason. You're moving a lifter, a pushrod, a rocker arm, then a valve as well.
All this equipment in older cars is very heavy and takes a lot of energy to start and stop. Thus you need a lot of spring as well.
All together this means tons of pressure on small areas, thus need for more additives.
All this equipment in older cars is very heavy and takes a lot of energy to start and stop. Thus you need a lot of spring as well.
All together this means tons of pressure on small areas, thus need for more additives.
IMO there is no need for a 15w40 in the 8.2.
Mobil 1 0w40 or Mobil 1 turbo diesel truck 5w40 should provide more than enough protection for the flat tappet cam.
The 15w50 only has 100ppm more zinc but startup wear in cooler temps will probably offset that difference. 0w40 would be my choice.
Check the levels out..
http://www.mobil.com/USA-English/MotorOil/Files/Mobil_1_Product_Guide.pdf
Mobil 1 0w40 or Mobil 1 turbo diesel truck 5w40 should provide more than enough protection for the flat tappet cam.
The 15w50 only has 100ppm more zinc but startup wear in cooler temps will probably offset that difference. 0w40 would be my choice.
Check the levels out..
http://www.mobil.com/USA-English/MotorOil/Files/Mobil_1_Product_Guide.pdf
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