GEO Update: tires
Finally got around to putting low rolling resistance tires on the Geo. They certainly make the ride much stiffer but remove the handling problem I was experiencing on the overinflated regular tires I was trying to simulate LRR tires with. I still am unsure if there is a benefit or harm in running 5W30 oil compared to the 10W30 recommended for the Suzuki engine. You certainly get more tappet noise when the engine is cold with the 5W30 oil.