Hi Croc, funny you should mension the oil temps - I tracked CSR regularly for four years and my oil temps have never been a problem. I had 2.0 Duratec engine from R500 Duratec Superlight mated to CSR 260 cooling and lubrication system with Caterham 6 speed box and Stack dash. the car had a massive CSR radiator tilted forward with the plastic lip funneling the air to the top nose cone cut out, no oil cooler and modine oil/coolant heat exchanger in oil filter housing. Despite full throttle at Silverstone or Brands the oil temp has very rarely gone over 100'C. Immediately down to about 94-95'C on the cool down lap. High oil temp has never been an issue. I've used 10W-60 oil viscosity. Changed to 620R SV now, my CSR is up for sale here: https://www.sevensandclassics.com/showroom/caterham-csr-superlight-500/