Never ran that oil, but 5W20 is fine. Only the very early 2000 Focus was spec'd for 5W30 and all the previous Zetec engines. The subsequent Zetec Focus models were spec'd for 5W20 as it gave a slight jump in mileage. Many people here run both with no issues as nothing changed in the motor to require a different oil.

 

I've ran it/run it, 5W20 is fine.

The 25,000 miles is for cars with low mileage, with yours being over 100,000 change it more frequently. It'll still allow you to go much longer than any other oil.

 

Then i'll run it! I just hope they pay for tha damage if the motor goes Boom!

 

Why would it go boom?

 

i have ran it in my car for unknown miles. i change it once a year in May and like i said i dont pay attention to the mileage. I have ran it since 95k~ and im at 177k now. I run the 5w-30 but that was before they had come out with the 5w-20. That i believe is new for this year.

you wont have a problem with the oil or the car going boom. Just make sure your not burning oil or losing it out somewhere and check the level every once in a while.

 

if the motor goes boom, and a mechanic finds the cause to be amsoil, they will pay for a new motor.

i run the 25k mile oil, i ran 0w30, and it did perfect in my focus. ran it for 15k miles if i remember between oil changes. i am going to run it in my corolla race car also. if you have doubts about how long it can go, they also sell oil test kits, so you can take a sample of oil, and have it sent to the lab( also good for finding any possible lurking problems with your motor.)

 

Going that long of an interval, I would use 0w30. Also curious as to the results.

 

One of the other things you can do is get a bypass kit. use the bypass kit with a full flow filter and you can get damn near unlimited mileage from the oil.

I was talking to a guy that said he used the bypass kit and he would get his oil tested every so often (i forget the interval) and just top it off. he would wait for the lab results to come back and if it was alright he would keep running it and if it needed changing he would do so.

The bypass kits filter down to like 1 micron

 

Bypass filters are a truly excellent idea if you want your engine to run forever, but generally speaking the key factor with extended drain intervals is the TBN, something the bypass filter will do absolutely nothing for. The best way to get the most life out of oil is to do routine sampling over some shorter intervals to find the wear rates / additive depletion rates, then guess what your next change interval should be based on them and sample again. It takes a few times though to get it right, but every engine is a little bit different.

I would bet your maximum change interval is around 15,000-20,000 miles, and that your TBN will run out well before 25,000.

 

I use 5W30 in summer and 0W30 in winter... but I only go a bit over 16K miles on the summer stuff (since it's in ~7.5 months) and less than 10K miles on the winter stuff. I wouldn't want to use it the whole 25K miles on a modified engine... mine is mildly modified, probably ~150+BHP/145lb-ft Tq, and I don't like the idea of leaving it in all 25K. It's a very smooth, good oil. It comes out real dark after that time (doing it's job), with no streaking on the dip stick and it still drips just as nicely as the fresh oil.

 

also,realizethat if you are in a harsh climate, or under harsh conditions for your oil, recommended interval is 15k. this includes dusty areas, stop n go traffic, little to no warm up, racing,etc.

 

I've run Amsoil for years in most of my vehicles. I run the extended drain stuff but never as long as they claim you can- not saying it won't last but I'm old school so I usually change about 15k to 18k in and that's with a filter change half way. I have three vehicles over 130K that are driven hard and they have not missed a beat. I'm not sure about switching to a full synthetic in higher mileage vehicles- I started mine off at the 5K mark.