i just used mobil 1 5W-50 fully syn for my inspira's 4b11. sounds so much better and not as harsh as it was on petronas syn800.

morning starts is where the mobil1 fully syn shines, very smooth and dont have to maintain at high rev during idle, unlike the syn800, loud and takes a long time to stabilise

it really makes the syn800 feels like crap. but again, the price is almost double, so it is hard to compare.