AutoZone sells Castro Syntec 5W-40. Just did mine at 1000 miles. 4.7 quarts with filter change (does not include cooler change..... if you have them). Toyota designed and built the motor. If they recommend 5w-30 I am sure it is fine for normal driving. It will just not give as much protection under extreme conditions like track use. Any synthetic should be better than the mineral based oil Toyota recommends. Toyota designed and built the motor. If they recommend 5w-30 I am sure it is fine for normal driving. It will just not give as much protection under extreme conditions like track use. Any synthetic should be better than the mineral based oil Toyota recommends. Toyota also does not mount the engine in the tight engine bay, nor do they feel the need for the oil coolers. Then again, Toyota has had oil related problems with cars that have that engine installed, and Lotus doesn't see to be having those problems.

If Lotus requires 5W40 oil in the engine, that's probably the best choice to use - especially in consideration of the warranty requirements. AutoZone sells Castro Syntec 5W-40. Just did mine at 1000 miles. 4.7 quarts with filter change (does not include cooler change..... if you have them).
Yes, found them there at Autozone. Castrol Fully Synthetic Syntec 5w-40. 6 quarts, i plan to use 5 and keep one for spare. NAPA carries Valvoline SynPower 5W-40 at least here in San Diego.