I usually change the engine oil and filter every 5K on my '86 147K MK2 Golf GTI K-jet with Quantum Synta Silver semi-synthetic. Very happy with it I have been!
Unfortunately, I have just mistakenly put in Quantum Synta fully synthetic as I did not think to check the label as I was in a rush and it came in the same silver bottle as the Synta Silver does. Only when I ran the engine for the first time and noticed that it seemed to run markedly noisier did I think to check.
Is it OK to run with the fully synth for 5k miles until the next change or should I be sufficiently concerned to immediately replace it with Synta Silver?
