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ABayliss

The compression test won't necessarily find a leak or head gasket problem - particularly if it's a very small amount requiring top-up only once in a while. If the coolant level was fine when the car was inspected and there was no indication of hydrocarbons in the system when the inspector did the tee-kay test, it should not a head gasket problem.

pat.bateman

Thanks for your help. I took it into my mechanic on Saturday. He had a look over it and couldn't find any issues with the head gasket or the hoses and reckoned the coolant levels were fine. The Mondeo is a bit confusing for me because it has a plastic overflow tank and not the normal radiator cap that you see on Japanese cars. His advice was to always monitor the coolant level every fortnight more as a precaution because the engine components are aluminium and any overheating will cause them to warp which requires a complete overhaul- a job which can be in excess of $4k!

ABayliss

That's great. Pleased to hear it's all in good health - seems that the previous owner was just ensuring he had the correct coolant on hand in the event he needed it, rather than due to any fault with the car. Meticulous people like that are good people to buy from as it's a sign they have taken good care of things.
You can relax and enjoy your new car now!

pat.bateman

Thanks for your help. One last thing- bit confused on what fuel the car should run on . Ford tell me 91 while my mechanic recommended 95 for better fuel efficiency and longer lasting spark plugs and less engine maintenance. I have a smart fuel card which brings down the cost of 95 so should I just use that? Will it better my fuel efficiency?

ABayliss

Research we've done on this subject has found that if the engine is designed to run on 91, there's no advantage in using 95. In fact, it will cost you more to run a 91 octane engine on 95.

pat.bateman

Thanks the compression ratio for this car is 10.8:1 by the way. Does that make a difference?

ABayliss

No. Believe it or not, the latest Mazda engines run a 13.3:1 compression ratio and run on 91.