I have a 2003 F150, 4.6L V-8 engine. It's a 4x4 with a 5-speed manual transmission. How often should I change the engine oil? I'm thinking I'll change it every 5,000 miles. I just run it on roads--no off-roading, and not a lot of heavy or abusive use. I just bought the truck. The owner's guide refers me to the scheduled maintenance guide, and I don't have one. In my opinion, the 3,000 mile-oil-change schedule is more frequent than necessary.

I just did some reading on the Forum, and, in a nutshell, here's what I'm getting:
3,000-5000 for conventional oil.
Maintenance Guide says 7,500 miles (I read that here, not in a book.)
Fully Synthetic Oil: 10,000-15,000????? That sounds like a lot.

I'm still interested in hearing what you have to say. Thanks for the help.

 

...and here's mine: Conventional lubes, 3000 miles or six months. Part synthetic lubes, 5000 miles or six months. Fully synthetic lubes, 7500 miles or six months. Change the filter as well. (I like Motorcraft filters.)

Some fully synthetic lubes are formulated with very robust additive packages that may run safely for 10K miles or more, but I'd be a bit wary running that far out.

I guess an inspection of the appearance of the oil can help in determining change intervals. If the stuff is dirty, dark and brown, it's probably due a change.

FYI: Wal-Mart's Supertech fully synthetic oil is now sporting API service rating N. I've seen no other major having been improved to that maximum rating....not to imply all other brands have not.

 

Ford says 3000mi is for severe duty useage. You can easily do 5000 miles with full synthetic, I've done 7500mi changes with Royal Purple and haven't had any problems.

 

For the Last several years I have been using AMSOIL along with their filter and with this product, the specs call for 30,000 mile oil changes or one year which ever comes first along with an oil filter change every 15,000 or 6 months. Top of the oil after changing the oil filter

 

I have a '02 4.6 and have done oil/filter change every 5k ( I average 4 to 5 months time in that mileage) with synthetic oil. At 108k miles, not probs. I agree with Kattumaram. Use the good stuff and error on side of caution. I go to Walmart and get the motorcraft filters and mobile one 5-20 that is recommended.

There is a 4.6 in a crown vic running around town here that began life as a police car and then retired out as a taxi. The local Ford dealer says it has over 340k miles on it. it is serviced every 3k miles. So far, no engine problems. Some are just lucky, some are lucky and serviced well. Here is to affording the gas to drive to 340k miles.

 

 

We run synthetic in my family and go 7000-9000 on oil changes, and 4000 on conventional oil

 

new oils are quite a bit better than in the past so id say go 5000. work in a shop an sadly do all the oil changes, most personal vehicles that come in for a service at 5000km or 3000miles the oil is usually very very clean. Expecially on new engines, however company trucks come over due for services by 3000km and they generally are dark but that's worst conditions possible. Try it out an see how dirty the oil becomes id make my judgement by the vehicle.
my 2cents

 

This is one of those things were every body has something different that hopefully works for them on the the cars we have that use conv oils I change them at 3K and 4K on the ones that use the blended oils...

 

the best thing to do is have your oil tested after so many miles, either it be 3,000 or 10,000 miles. with the oil analysis you can see how much life is left in your oil and can adjust your oil change intervals accordingly, all of which has to do with the quality of the oil being used and the driving condition.