difference between 89 and 90 SP36

[John Severs]

can anyone tell me, are there any appreciable differences between the 1989 and 1990 SP36? not too concerned with interior layout differences just thinking powertrain or mechanical differences? Thanks in advance for any help.

[Kb1jkn]

Over the summer I was able to tour a 90 SP to compare it to our 89. With the exception of a few interior differences like switch panels instead of our household switches, the dash being black rather then our grey , and the landing lights being the flat rayline style over our round aimable lights nothing of any mechanical difference was noticed. Same engine, same transmission, same Onan generator, same exhaust exit.... Even the 91 SP , which has many visual differences over the 89, 90 is the same running gear under it all.

[Bill Pape]

The internal heating system should not be a reason to purchase or not purchase. But BB changed from Suburban propane furnaces to Primus during the SP Model years.
We have three Suburbans. They can be cleaned, serviced, repaired, parts and replacements are still available. They are noisy, but can put out a lot of heat in a hurry. Primus is smooth and more quiet. But are becoming obsolete and parts are hard to find. Primus can be replaced with a diesel burner. Both have electric toe heaters, this is a very desirable heat when on shore power or generator. If you are curious there are many posts on this topic, Just use the forum search.

[Kb1jkn]

I will say after one year of ownership we have yet to use our suburban heaters when camping. The toe heaters and the larger electric heater in the bathroom have provided more than enough heat for us when we have needed it. I did forget to mention the heater change over that Bill talked about, good catch. As nice as upgrading the Primus to a diesel hydronic would be I agree that it shouldn't be a deal breaker.