Just bought an 04 Dakota QC 4X4 4.7L with 89,000kms on it. I just switched the plugs to NGK and had the oil filter changed to NAPA GOLD and am now running Mobil 1 5W-30. How long can I expect the Mobil 1 to last before I have to change it and the filter?? I put on about 20,000kms a year. Thanks

 

i say about 3k miles depending on how u drive. personally i would go with castrol syntek. its a mixture of reguar oil and synthetic. synthetic oil gets really dirty. but thats just my opinion

 

why would syn get dirty faster?

Normal oil is thicker then synethic, syn splits up when being moved around causing less friction meaning less heat = longer lasting internals...

all oils get dirty after 3-5k miles unless you have a perfectly clean engine.. hard to do to unless your air/fuel is a perfect mixtute and you burn 100% of your fuel and produce no carbon... gl.

Syn will help the motor last longer, and run smoother, its a bit more expensive but if you do it yourself you can get away with about 30$ oil change.

Shops useally charge like 50-80$ for syn oil changes..

also to answer your question i would change your oil about every 3k.. if your tight on money you can probably run it to 6k and get away with it...

 

the synthetic oil should last a little longer than conventional oil, however you're still using a napa gold oil filter, which means you should change it every 3k miles. I use the K&N gold racing filter and mobil 1 synthetic 5w30 in my 2001 and i change it about every 5k miles. most of the time the oil doesnt even look that dirty but i do it anyway, just because i want to keep it forever.

 

I try to change Mobil One every 5,000 miles or 200 hrs of engine operation.
{which I think is about half what it could do}

I try to use the "long" oil filters and change them every 500 hours of engine operation (about 20,000 miles for most drivers)

If you allot a set amount of money to lubrication
you get the best use of this money
by changing the oil more often
and the filter less often.

This is because filters increase in filtering capacity as they get partially dirty and most filters can go a long time before their 10 psi 'delta' pressure bypass valves open.....and even then the bypass only opens when the rpms of the engine are very high. This does not cause problems.

Getting rid of water, acids, and blow-by hydrocarbons is the reason to change oil more often.

I would not argue with someone who changes conventional oil every 1500 miles and claims this is a superior use of money.

 

Yeah I run Mobil 1 and change at about 4000. I figured I should at least get an extra 1000 for using synthetic over conventional. Plus I only drive maybe 10-15 miles a day.

 

the synthetic oil will last for ever as long as its clean. but the oil filter will need to be changed around 4-5k miles. u might notice if u run syn for over 4-5k miles your engine might not be as responsive, but thats just because the filter is clogging up. u can run syn oil till its turns dark or black(which means its dirty, and time for a change) but you need to change the filter every 4-5k miles. keep in mind that when u change the filter u need to top off the oil to the full amount that the engine needs. thats the great thing about synthetic oil is that it doesn't breack down. so run it till its dirty and then change it. thats why the filter is higher on the engine, so u wont loose all the oil when u change just the filter...

 

Perhaps the first time you use synthetic you will notice its "dirtier" but thats because its actually cleaner, and is cleaning your engine. (Very similar to the diesel guys that convert over to biodiesel, they will have to change their fuel filter sooner than usual because biodiesel is actually cleaner than regular disel, and is cleaning out the system).

I wouldn't recommend going more than 3-5K on any oil, unless you do oil analysis.
Synthetic oil is still exposed to all the same combustionby-products as regular oil, and for that reason, intervails shouldn't be extended too much without oil analysis to tell you "its ok." This isn't the case with transmissions, transfer cases, and axles, which basically sit there and circulate.
Just because you use synthetic doesn't mean your engine stops wearing out, and the oil does pick-up stuff that is smaller than the filter will catch .

 

Hank, what engine do you have and what filter brand/part # do you use?

 

I use castrol GTX syntec and change it every 5,000kms. and use a fram or fram synthetic filter.

every truck I've had, I've use synthetic in them.