I have a 99' 2.4L DOHC, auto, with 114,000 miles. I recently switched over to valv. max life, a synthetic blend, for my last 3 oil changes and I use a pretty good filter(napa gold), but my friend has a Honda fit and suggests that I should use full-synthetic for my next oil change. He recently went down in weight to 0w-20w mobil 1 oil.

I've heard statements before about never going full synthetic if the car has used conventional for any long period of time, as in the case with my car. Is this true? Does anyone run full-syn on their stratus? Does anyone have experience swapping to synthetic with a high number of miles?

 

Not quite as many miles but .... Switched my R/T with 71,000 over to Amsoil 0w-30 with no problems thus far

 

I've heard good stuff about their oil. Curious. Did you use a blend or conventional before switching?

 

Bought the car with 64,000 just over 2 years ago, I've run PYB, GTX, Walmart brand .. (Super Tech?) and PP. I'll be trying Castrol Edge for my next OC.

 

Honestly, I think a good oil filter can help more so than the choice of oil. As long as we're not talking the pits as far as oil, if you've seen the difference in a quality filter like a K&N or Mobil1 compared to an entry level filter, like on my friend's Honde Fit, its like night and day. He's the type of guy to go 7,500+ between every oil change on that kind of car, so in that case the oil and the oil filter need to be able to last.

If you're doing the "standard" 3,000-4,000 miles then its not as big of a deal, but I use Napa Gold filters and have used Bosch Platinum as well. I just don't want to pay the extra for the K&N or Mobil1's. I'm already paying for a really nice filter, why pay another $5 for a small jump? I guess I'd do that if I were going to go for the long mileage in betwen oil changes. The OEM filters for our cars are outperformed by the hi-end aftermarket filters easily. Even though Dodge has the one company contracted for parts, was it mopar? I forget.

Basically, what I've found out through research leaves me uncertain. Two sources said to not switch to full synthetic if you have any existing oil leaks. Also, that there is a possibility of blow-by and leaks appearing at seals when the synthetic oil cleans them because of deposits having prevented a leak from appearing. The remedy to this is apparently to drive only about halfway between your initial change to synthetic, say 1500 or 2000 instead of 3000, and gradually build to the longer period between changes. The reason is that while synthetic maybe better in the end, as you can see, you may have issues with leaks appears and having rings unseat during the cleaning process. In the end, you get the benefits of the cleaning/protection that the synthetic oil brings, but also won't allow the potential for sludge and deposits from a dirty engine to kill your car during this conversion process, so to speak. The oils blend together fine, but its the additives and detergents that can cause problems if you just switch to full-syn and push it to 7,500+ miles on your first run.

Apparently, in the UK they drive 10,000 K in between oil changes.

https://www.mobiloil.com/USA-English...o_Mobil_1.aspx

http://www.stangnet.com/mustang-foru...ml#post6375475

 

I run Royal Purple 5w-30 and a K&N filter. Never had any problems. This is the combo i use on all my cars at 7500 betweem changes. No problems TD.

 

Thats awesome. How much do you pay for RP and which filter do you use?

 

I get it at Autozone bought $8 a quart. The filters just the K&N gold series.

 

Hmm, my autozone only has RP for Gear Oil. Personally, I'd like to take apart the K&N gold oil filter(I use napa gold lately) to a Mobil 1 EP filter. I think they are both made by the same company. Good deal. The Amsoil filter is just crazy expensive, though.

 

Both the autozones by me carry it. it would be cool to take them apart and see the difference if any.