Oil change

I have a 1991 miata with 90,000 miles and a f150 with 1500 miles i drive each less then 5,000 miles a year I am thinking about changing oil to synthatic once a year what do you think

I think it’s a great idea. What schedule do you currently change oil on?

I think you could use a normal non-synthetic oil and change it once a year. That is all you should really need with the kind of mileage you are putting on your vehicles.

I would go with twice a year. It may be overkill. With that little use the acids in the oil would cause me more concern than the mileage. Lots of sitting and condensation. Even if its overkill, the extra cost is not that much, is it? This is why the mfg has mileage and/or time intervals for service.

I agree with mountain. I think it is a good idea. Most modern oils should be able to handle that driving, but synthetic will do a little better. I can’t think of any downside to using synthetic. Of course you should choose a synthetic that meets all the requirements (S number and viscosity) that the owner manual calls for.

The downside to synthetics is cost. But that may be mostly offset by doing it once per year rather than twice with a natural petroleum product. The convenience should offset the rest.

Regarding the F-150 with only 1500 miles on the odometer–since this is apparently still under warranty, you need to follow the guidelines in the Ford maintenance schedule that came with the truck. Otherwise, you risk voiding the warranty.

Bear in mind that all service procedures have both an odometer mileage value and an elapsed time value, with the proviso–“whichever comes first”, and changing the oil only once a year (even with synthetic oil) will violate this maintenance schedule.

If you want to keep the warranties in force on the F-150, you should adhere to Ford’s guidelines. With the '91 Miata, you can do whatever you see fit to do.

Take a look at your oil filter,does it say “factory installed” or something similar? You don’t want to show up at the Dealer for warranty work with this filter installed (if its time was up) some “factory” filters are a unique color,some what of a check if you change it as required.

The oil change interval for normal service on the F150 is at least 5000 miles so yearly would protect the coverage. The only way you could go wrong with your plan is if the mileage is predominantly short trips. If you fully warm up the vehicles when you drive them, you are good to go. If you don’t, you might need to change it more often. The Ford probably calls for semisynthetic. You can get that motorcraft stuff at Walmart for a good price as well as their filters. Both are good products and bear a good price.

Warranty coverage can not be withheld due to using non-OEM maintenance parts including filters, unless they don’t meet the manufacturer’s specifications. I don’t know of any filter available in North America that does not meet OEM specs with the exception of K&N type air filters.

You miss my point.Remember earlier last week with the woman who claimed the dealer sold her a abused car? The woman claimed the dealer said they prepared the car for resale. The woman produced a photo of the oil filter and on it it said “factory installed” the woman said this proved that the used car reconditioning people did not change the oil since the filter was the one installed by the factory (the engine siezed).The factory uses these labeled filters to catch people that dont change their oil. I am not saying anyone has to use a factory filter.

What I am saying is dont show up with a car with 20,000 miles on it and the same exact filter that was put on the car when new. They will know it hasn’t been changed.

I can’t understand how you took my post as one that says you must use a certain filter,you are way off.