[beemergary]

How often/runs/etc. for like Amsoil? Thanks 63 tempest 421sd-61 tempest wagon 421sd

[Ron H]

Does the engine sit over the winter in cold temps?

How often and how much are you trying to be faster at the track?

How high do you rpm the engine?

Street miles?

Some guys change per event, every couple of events but most once a season for a race application.

Street 2500 - 5000 miles?

[60man]

I run AMSOIL 5-20 Race Oil..Have been for several years now.
I start off fresh and then just change filter and top off every 35-40 passes.
Mostly just to cut open filter to check..
Bearings have always looked good..

On street cars I used to change filters and top off at mfg change interval and then drop oil & filter on second due interval...

[beemergary]

Gets about 30-40 max runs a year @ 6200 rpms and a few street miles and yes it spends the winters in Michigan. I do run 15-50w in it now.

[Probird]

I'd change it once at the beginning of the season with that many runs.

[Ron H]

^^^^ x 2. Below freezing temps cause oil to break down. So even with few runs and street miles it is good to change in the spring just before the season starts.

[vin63]

Originally Posted by beemergary

How often/runs/etc. for like Amsoil? Thanks 63 tempest 421sd-61 tempest wagon 421sd

There are a lot of factors involved. In a race application, the oil change interval is usually done so frequently that the effective life of the oil is not completely utilized, due to factors such as fuel dilution, etc. But, if you really want to know, send an oil sample to a reputable lab for a UOA (used oil analysis) and be sure to ask for the TBN (total base number). Just about all of the labs provide a summary, chemical composition and viscoisty levels, etc. I do this for my daily drivers periodically (every third oil change, or so) since I practice extended drain intervals.