So, I got my 95 3.4 v6 at about 146k and have been running 5w30 mobile1 synthetic on it for almost 3yrs...Now the engine is just under 162k. My buddy told me to switch to regular unigrade30 weight or just go to 20w50 but he says get off the synthetic bc it has a wicking effect on the engine -basically preserve the engine. I've had mixed stories about what to go to or just to go to 10w30 bc of spring/summer. Just kinda want some advice, the manual says not to go to higher viscosity but my buddy says otherwise. Also I've heard more and more people are mixing synth and reg oil as well in a 50/50mix.... So...thoughts and guiding hands?

 

the lower the number the first number on multi grade the better for cold cranking

the higher the 2nd number the better for prolonged running of the engine at high rpms ie: 80% of redline

so, 5 w 40 (is there even any 5w40) would give you good low temp protection as well as high revs. 5w30 is fine for most applications because nobody really does prolonged high rpm's


next, the larger the difference in multi-grade ie: 5w30 , 5w20 is that the oil with the greater spread could breakdown sooner during prolonged oil change intervals (called thermal breakdown). Again, those are extreme uses and not the avg person who changes oil every 5k miles

about blended oil, you can buy synthetic blend oil and it's priced between traditonal and full synthetic. Motorcraft tends to be the most affordable

as for your vehicle, I'm not sure why you run synthetic other than to spend more money but you'll be fine staying with it or going to regular oil and change it every 5k (more frequently if it's all city driving)

if you use the search function on this forum as well as others, you'll find a gazillion threads asking about oil. This makes a gazillion and one.

You will receive lots of opinions, including mine, and we know what they say about opinions

 

Yeah that's where I was just really confused because I have been reading all those threads at work and it's just a bit frustrating to piece the info all together lol

 

IMHO, you're wasting $, just get the cheapest full synthetic -- I am using WalMart SuperTech full synth in both of my Camaros and have been for years...

 

if the oil pressure is running a little low switch to 10w40

 

If all you do is put the oil in and take the car on a highway trip, you can consider that light duty driving, and you can go a longer interval between oil changes. But with cold weather, stop and go traffic, heat of the summer, etc., (the kind of "normal" driving a lot of us do), that's considered "severe", which falls under the 3k mile change interval, with conventional oil. Conventional oil starts to break down from day 1, synthetic takes a lot longer before it breaks down. You can easily go 5k miles to conventional oil's 3k. When you also factor in the oil filter getting changed less often, and you having to take the time to change the oil less often, synthetic oil doesn't cost you more, it actually costs less. Do the math, then stick with the synthetic. And what the heck is this "wicking effect" your buddy is talking about?

 

Except is the oil filter going to pass its useful life before you change the oil when going up to 5k and above -- that would be the question I would have. Plus how would you know without tearing one apart?

 

Nope. An oil filter filters until it gets clogged. If you can clog an oil filter in 5k miles, you have big problems inside your engine. Then you should worry more about changing your engine, not the oil.

 

He was talking about eats at the rod bearings and seals they also apparently are known to attack sludge that was previously providing a seal on a gasket like on a rear main.

If anything he gets concerned bc on the gauges the oil pressure starts at the half mark and then by the time the engine fully heats up esp. in city driving it dips a bit low for his tastes, like at the white notch above the red line. But it never drops to the bottom red line though. He keeps asking me to get an oil with a higher viscosity like a 20w50. I'm like uhh why not a 5w40 or 10w50? But yeah I'm just wondering what's best for my engine. I drive it around town and maybe highway drive it for 30min a day during the school year. I do change my oil every 3-5k or 3 months which ever is sooner, but yeah just kinda concerned bc of it's age and mileage that's all.

 

What about a dusty environment -- that is a factor... In fact, vehicle oil life systems do not account for this, and I have not lent trust in them.