I know this has probably been discussed and I've searched the forum a bit but just incase something new has popped up. The guy at valvoline said most guys that run full synthetic oils change about every 4500 miles instead of 3000. Whats the verdict on this? I run the 5-20 full syn.

 

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With Syn, every 5000mi you will be fine, that is the interval I use...

 

My manual, as well as many other manuals for older vehicles, says every 5,000 miles with no mention of synthetic.

With that said, I still change every 3,000.

 

Valvoline 10 - 30 non syn, every 2,000 miles - supercharged.

 

Just another boring oil thread

Keep changing @ 3000 and your motor will last. My 5.4L two valve is one bad a$$ motor @ 226,000 miles, never stop running that Castrol 50/50 Syn.

That oil has sold me for many years.

We just bought another 98 with a 4.2 recently. The previous owner kept all his oil change receipts, but man , when we changed it for the first time that oil was nasty and the filter was an solid blue color with no writing on it - not sure what make the filter was. The OD says 86,000 miles and it's leaking oil from the front of the motor some where . It's hard to see where it's coming from and it doesn't puddle on the ground.

I'll find out where it's leaking when I got more time. The receipts were all from a Pennzoil quick oil change place.

The 4.2 runs good tho. I'm just unsure about the filter and oil they used.

 

Ford recommends changing the oil every 5,000 miles. There is nothing wrong with changing it every 3,000 miles, but you can run it 5,000 miles.

 

I'm running full synthetic and changing it every 7500 miles.

 

I think it's funny that in the US, I hear change the regular oil at 5000 miles, in Canada, it's 5000 km's or 3000 miles. Canadian's will have better engines, ha, kidding, damn metric system, eh? With synthetic, I'd see how it looked at 5000 miles and go from there, it's a toss up because everyone does the oil changes at a wide range of mileage. I'd go to a Ford dealer and see what it recommended in fully syn cars like the GT 500 or something that runs full syn from the factory. I know those cars run like a 5w-50 full syn, but it ought to give you an idea of a good interval.

 

Under normal driving, every 5,000 miles with dino oil is just fine. IMO, unless you really work your truck hard, you are just throwing money away changing dino oil every 3,000 or synthetic every 5,000.

 

In the winter months I'll let it go a bit more. Thermal viscosity break down happens more in hotter engines. In the winter months I'll let it go to 6000 sometimes but in the summer I always make sure the oil is fresh. I never use penzoil. I dont know if its true but I was once told penzoil has parifine in it. I only run synthetic in my 71 mach I and I only change it in that once a year in the spring. It only gets 2-3k ayear on it. My work van 97 E-350 with a 5.4 gets changed the way I described and it has a 195k on it and it still runs like new. never used synthetic in it ever. mostly quaker state at Q-lube..

 

You want to change the oil more often in the winter because the engine doesn't get warm enough to "cook" out the condensation. That water collects in the crankcase and forms sludge that will eventually clog the oil pickup or even oil passages and starve the engine or parts of the engine of oil.

Getting to the original question, if your using a good quality brand name oil and filter you can safely go anywhere between 3-5000 miles between changes.

 

Winner.

 

I have 54,000 miles on my 5.4, does not use oil, no leaks. I change it between 3500 and 4000 which is about every 2 months. Motorcraft 5-20, Motorcraft filter, at the dealer for $28.

 

The manual says 5000 miles. I've been on that schedule for 10 years (long before the manuals went to 5K). That's with regular old Dino oil.

The service departments in my area all say the new standard is 7500 miles. I see no reason why you can't go 7500 with synthetic. Change it more often if you want. I own lots of oil stocks and appreciate your business!