I have a 2008 Ranger 3.0 engine 4x2 which I have been running Mobil 1 synthetic oil in. The mileage is about 6700. When I had my F-150 I used to use Amsoil and liked it a lot. I'd like to switch from the Mobil to Amsoil but I see that the 25,000 mile stuff is not available anymore. Is Amsoil still as good as it used to be? The 7500 mile oil seems to be available so would this be a good choice? I appreciate your input.

Thanks Flyguy

 

I use the Mobile 1 in my Ranger. My Porsche recommends it so I figured if it was good enough for it my Ranger would appreciate it as well. I also run premium fuel through it although I know it is not necessary. It makes me feel good though. 140,000 miles and still going strong.

 

Amsoil still sells the 25,000 mile stuff. Amsoil is still the same as it used to be.

I used to use the Mobil1, then I switched to a real synthetic and never looked back. I currently use Royal Purple. Amsoil is also a great product and I would consider to be about equal to RP, and would use it as well, except in my area Amsoil is harder to find. Redline is great stuff too. Those three are the top tier performers.

Penzoil, Mobil1, Castrol, and others are not real synthetics by the strict definition. I stopped using Mobil1 after trying in in the place of RP once. While the color of the oil is not always a perfect indicator of oil condition, it is pretty safe to say that the darker the oil is, the worse condition it is in. I run RP about 15,000 - 20,000 miles per oil change interval. I put in the Mobil1 and checked the oil on a regular basis. Same engine same conditions, and I could tell the Mobil1 was oxidizing much faster than the RP. After about 9,000 miles I changed it, I was done. When I replace my RP at around 20,000 miles, it comes out a brown color. When I changed out the Mobil1 at under half that, it was very black. It was also thicker than it was going in.

What Mobil1 has done is a different group stock, which through refining and additives, they have gotten to be a much better oil that regular oil. But under the original definition, synthetics were made from group Iv ester base stocks. Oils made from these compounds do not need detergents added, they have very strong film strengths yet have good viscosity qualities. They can hold more particles in suspension. They do not easily oxidize, and they can protect other things from oxidizing. They have intense heat resistance and excellent shear strength.

Oils like Mobil1 are made from lower quality stocks, and while they can be made to act like GroupIV, they achieve this through additives. The oil itself does not have the heat resistance or shear strength of real synthetics. It is the additives that make these oil perform as well as they do in tests. But once these additive start to wear out or break down, and they can no longer hold acids and dissolved chemicals in suspension, the oil starts breaking down. You have to realize, that every oil molecule in a groupIV oil is a detergent, whereas the synthetic look alikes have to have detergents added to them.

So in response the the original question, yes Amsoil is every bit as good as it used to be, and still lasts about 25,000 miles. Mobil1 costs almost as much as the real synthetics, but it has nowhere near the lifespan. I demand oils that can actually hold up to the extremes.

 

I still wonder if it's cheaper to use normal oil and change it more often, or to use the synthetic and change it less often. What's the cost breakdown? Assume that it's going to be done with free labor, i.e. DIY. Thanks

 

I just made the switch to Mobil 1 on my Jeep.

 

Bear River
so are you saying that by using Royal Purple or Amsoil I wound not have to change my oil for a least up to 15,000 to 20,000 miles. You got my interest now. I have been using Valvoline syn-tec blend. I have been thinking of running pure synthetic oil for some time now. but was not sure what to go with. do you just change out the filter then till you reach the mileage. and if so how often would you change the filter. I only got 3 oil changes on my 08 right now and if I switched no do you see any problems with the switch. Thanks

 

Bear, if you had said that you had both the Mobil & RP each analyzed after a set number of miles, and then found that the numbers proved one performed better than the other, you would have said something worthwhile. But to recommend one oil over another just because of the color is a poor way to judge it.

A person could actually say that the Mobil 1 is a better detergent oil than the RP because the oil is darker! The RP isn't picking up as much dirt and thus is lighter color!...

 

Uh oh, not another oil war on here! lol Call me crazy, but I think it would bother me to death to let my ranger go 15 to 20,000 miles between oil changes no matter what the synthetic I tried using. I'm happy with using my high mileage pennzoil 5W30 and changing the oil and filter every 3,000 miles. Maybe I'm throwing money away, but it just gives me peace of mind to do it that way.

 

Changing the oil is more than just changing the oil. It's a chance to look at all the mechanicals and see what's what. What's loose and needs tightening, what's leaking and needs to be topped off, what's dirty and needs to be cleaned.

 

But thats where you could be wrong, oil doesn't turn dark because of what its picking up. It turns dark when the oil molecules begin to breakdown and oxidize. True I have not had it analyzed, but between my two personal vehicles I have over 7,000 miles, both original engines. I think I know how to care for my engines.

I'd go with the Amsoil. They have a liability guarantee on their 25,000 mile promise. Thats why Amsoil and Redline is used in professional racing, not the other brands shown on the cars.

 

Personally I want what is best for my vehicles. If it is RP, Amsoil or Redline, I will change. I believe in taking care of the vehicles regardless of the cost. Just let us know what is best. Thank you.

 

edit, on my earlier post I accidentally said 7,000 miles. I meant 700,000 miles.

 

The oil you should use depends on your OCI (Oil Change Interval), type of vehicle and type of driving. Other forums, like Bob Is The Oil Guy (google it), have more than sufficient info for you on oil - should you take the time to read it. UOA's (Used Oil Analysis) will help you know how far you can stretch the OCI.

Quit worrying about the color of the oil and do an UOA instead. Don't forget to match the quality of your oil filter with what oil you decide to use.

I'll admit I'm old school, and probably silly - I tend to do short term OCI's, like 3K. Do the changes myself, and it gives me the chance to see the underside of my vehicle. As far as mileage records, my personal best is 349K on a '80 Malibu with a 229 C.I. (3.8L) - only put Dino in it, usually Walmart's SuperTech.

Good luck on your best to use oil journey!

 

The issue that I have with the UOA is the cost. It costs as much as an oil change according to my limited research, about $25.
So, just change the oil: unless you're using synthetic then do a UOA to determine interval.

 

I love that Mobil 1. It's the best among the Synthetics.