amen Johnny. We run Mobil 1 in our vehicles and change it every 5K miles. When I bought my 240sx back in '97 (new) I had the dealer change the oil to Mobil1 before I took delivery. Currently have the '00 Dak and '07 Escape Hybrid, both get Mobil 1. Only time i would not recommend syth is if you have an older vehicle with higher miles that has run dino all it's life as the syth will eat older seals. In that case i would use blended.

 

I have been using the Mobil One filters...the longer one that matches to the long Motorcraft FL-1

 

I've always gone 5k on mobil 1 oil and never had any problems.

 

Using a "Full" synthetic oil is a good start on longevity. Oil brands are a matter of personnal choice but with full synthetic oil, you need to change the filter every 5k miles and just top off the oil level. After a year, then do a complete change out. With synthetic oil, the only thing that breaks down is the chemical additives that help clean the engine. Changing the filter and "topping" off the oil level maintains that cleaning property. I personnally use "ELF" full synthetic 5W20 during the winter and upgrade to 10W30 in the spring. I do a Full Oil Change twice per year, but change the filter out every 3 months and add oil as needed. Over 75k on the engine and everythings just as if the engine was brand new out of the box. Hope that helps.

 

I've spent over 20 years driving 18 wheelers with engines that cost more than my Dakota and did oil changes every 30K miles with no ill effects and in fact I sold a truck with 1.3 million miles original on the engine. I used Mobil's DelVac 1300 15W40 full synthetic in that engine. The major difference in synthetic vrs conventional oils is thermal break down. conventional oils loose viscosity (thickness) when exposed to heat then cool downs over time. That's why with gas engines using conventional oil, the reccomendation is every 3K to 3.5K miles or 90 days, which ever came first. Synthetics will not loose viscosity reguardless of conditions (heat/cool down, type of driving, etc.).However, ALL oils have the same cleaning properties mixed or added to them. These chemicals are what break down the fastest and are what needs to be replenished. I personnally run approximately 15K miles between complete oil changes however I do change my filter (I use either Fram or Wix filters) every 5K mles. I top off my oil level as needed when I change the filter by adding either a quart of oil or Lucas' Oil Stabilizer. In fact, you could do the same thing I did for my 625 hp ISX Cummins, whenever I changed the Petebilt's oil, I added a 20% mix of Lucas' Oil Stabilizer and 80% Full Synthetic Oil. If Detriot Diesel, Cummins, Caterpillar and Mack authorize "Extended" oil changes (30K to 35K miles) without harming the warranty, there's something to be said when you use a "Full" synthetic oil.

 

3000 mile oil change? Is this the dark ages? Most car manufacturers recommend 7500 miles with conventional oil. With synthetic, like Amsoil, they recommend 15,000 miles or 1 year, whichever comes first. Mobile 1 synthetic is ok, but I'd use amsoil if you can find it. It is a little more expensive but they have been making synthetic oil for about 30 years for cars and recommend a minimum of 1 yr/15,000 miles between oil changes. Some taxi companies in NYC use their oil and change them every 30,000 miles (which is about a month for them).

 

ran amsoil in my CTD for 15k miles... did oil analysis at 8000 & 15000 and by the 15k analysis, it was shot. I also have a bypass filter that filters down to 2 microns.

edit: forgot to mention that at the 8k sample, 3 of the metals were at the warning level.