Just purchased a CX-7 grand turing has the turbo engine, going in for my first oil change with 5000 miles. Been told by the dealer not to use synthetic oil, but you could use it later like after 15,000 miles. Another thought do I always have to use the 91 blend, could the 89 blend do the same, just incase the gas issue goes crazy in the near future.

 

I have used Syn in all engines since the 90s! I have always waited till the 2nd or 3rd oil change! This allows for break-in etc. I have never had a problem with an engine! The Turbo does need clean oil so on my Legacy Turbo, I always changed at 3000 but on others engines, I waited till 5000!
The two engines on my boat get changed on a regular low hour basis since they are run at high RPM. I now use Castroil but in the past it was all Mobile-1 since it came in our Corvett!
The dealer at Mazda will tell you that Mid-grade gas is OK if the car does not knock and runs well! I run Prem though because the MPG is more than equal to the increase price and performance is better for mountain driving!

 

A couple of points:

• It is an old wive's tale that says you must wait five, ten, or even fifteen thousand miles for an engine to break in before running synthetic oil. True, there is probably not much harm running that long on conventional oil, but there is absolutely zero reason why you shouldn't change at your first oil change.
• You're running a turbocharged engine that relies on a high anti-knock rating (AKI) of the fuel. If you cheap out on the fuel you will reduce the power of the engine (the onboard combuter will both restrict the amount of boost fed to your engine and keep the ignition timing retarded), and you will reduce your fuel economy (here again, the computer will keep your timing retarded).

Long story short, switch to synthetic oil when you want to, and use the quality of fuel that Mazda recommends in your Owner's Manual.

 

Thanks, Blackturbo for the heads up. I always used Mobil 1 synthetic in all my cars and changed @ 5000 miles plus rotate my tires, just to keep everything in check. This is my first Mazda and wondered why the stress was 91 octane, had a PT cruiser with a turbo never had that problem, mostly used 89 and sometimes 87 got great mileage. I've used Castroil which also good, but been partical to Mobil 1, being an old retired refinery worker.

 

Thanks Shipo, for your advice, I'll get the first oil change by the dealer first... it's free can't argue with that, after that I'll use Mobil 1. I understand more about the computer that regulates AKI and will stay with the 91 blend and keep the performance.

 

I have always used synthetic on every car I have owned. I usually change over as soon as i get the car, there is no need to wait for the engine to "break in". I usually change it at 5,000 miles along with filter. I had one mechanic ask me what kind of oil I used as when he was changing the timing chain at 75000 miles he could still see the original score marks on the cylinders which usually go away at 20,000 or less miles. He was impressed.

Turbos run hotter and synthetic seems to handle this better than regular oil. I agree higher octane helps the most but computers now a days help with that too!

good luck!

PR

 

No, not exactly. What the computer does is effectively "detune" the engine so that it is safe to run on the lower grade of fuel. Said another way, running a lower AKI than is recommended will reduce both the engine's maximum power as well as its fuel economy.