My Father put me onto Millers Oils after reading the Doctor’s high regard for this British oil. We bought our 2006 Peugeot 307 1.6 HDi 90 at two years old and 24,000 miles, and it has been serviced by myself every 9,000 miles since, using Millers Trident 5w30 semi synthetic oil, although I know that they recommended their fully synthetic at that time. It has now done 102,000 miles, the engine is as quiet as a church mouse, and it has been 100 per cent reliable. My wife loves this car as she finds the diesel engine so easy to live with and wants to keep it until it is no longer fit for use! As it’s only eight years old, and rust free, I believe it should be good for 15 to 20 years, which will be a maximum of 250,000 miles. Some questions for you, if you could kindly offer your advice. Should I now change my service plan, or keep it as it is? Should I stick to the Millers Trident 5w30 5995 semi-synthetic? Our car has done 78,000 miles on this oil and it is just fine. What other things are best to keep this 307 running to its grave? Simply put, this car is relied on every day and has become part of our family, but it’s a bit like the condemned man – why feed him up when the end is inevitable? I am not too sure if you or anyone can help me here, but some advice and a little of your vast knowledge may help.
Alan Stribling

You’re certainly doing very well with that 307, aren’t you Alan? Well done! Great engine that non-intercooled turbo, and you’ll see an amazing number of original Citroën Xsara Picassos with that engine still kicking around. To be totally honest, I think the secret of what you’ve achieved so far is the frequency with which you have changed the oil. What grade is not too critical really and oils that you might think of paying more for to give added benefits are really oils with extra additives for longer change intervals, which is not really what you are after. Stick to the semi-synthetic Trident 5w30 I would say, and stick to your 9K change intervals. The very good mechanic to whom I sold my last ZX told me that brakes were the weak point (and I’m guessing Peugeot and Citroën used the same parts) and he had changed a fair few bits of them not too long after he bought the car from me – but then he did drive it hard I think, or maybe his wife used the brakes a lot! If you haven’t yet done it, you ought to change the brake fluid every three to four years, as old brake fluid picks up water and the brakes tend to go spongy when the fluid has water in it. Same goes for the coolant – it would be sad to lose the engine because you had some serious corrosion in the cylinder head or something like that. Get it changed, totally, every three years or so, as the corrosion inhibitors and other additives in it do get exhausted with time. I presume that you keep a close eye on the tyres. If you want my tip for tyres, try Goodyear Efficientgrip Performance. We put a set on my wife’s old BMW 320i and it rides very well, grips well, and they are very quiet. Shop on line for the best prices, and you’ll see chains like Black Circles who fit them locally. Hope I’m not teaching my Grandma to suck eggs! Otherwise I think you’re doing all the right things, and there’s no reason why you shouldn’t see 200K without serious problems! Many thanks for writing Alan. Best regards,
Doc Diesel

Alan replied:

Thanks for the advice – I will stick to 9,000 mile oil change intervals and the 5995 semi-synthetic. On tyres, I will give your advice some thought nearer the time, but we’ve been lucky to have been given a nearly new set of wheels and tyres by some one who upgraded, so we should be alright for some time. Perhaps we are not the average diesel car owner, as our main concern is what it costs to keep it on the road. The Peugeot was like new when we got it, and over the last six years it has gained some age-related marks, but this is of no interest to us as we will keep it until the end of its life. With an average of 64mpg on the computer display, we would be out of our minds to think of changing such a good workhorse. Thanks again,
Alan