>I also understand that synthetic oil (SO) shrinks seals. A common
>that becomes costly evident with RX7 owners that use SO after a period
>time. Even though I still use it in both LBCs cars, does any one have
>insight into this?
Yes, during the first few years of the introduction of Mobil 1 they did
not include seal swell. There were some problems with gushing oil. That
has been remedied for many years.
I know that RX7's have had oil consumption problems, I do not know if
there is a correlation other than using synthetics in a worn engine will
result in very major consumption. The sliding seals in a rotary may
constitute "worn" compared to a piston engine rings (conjecture on my
part). High consumption may be related to it's good cleaning properties.
All my engines have appeared much too clean for the miles they have on
them. I suspect any buildups which help keep the oil in may be removed,
with resulting leakage.
Hillsdale, New Jersey
1960 TR3-A TS69032L
1974 Norton Commando Roadster