Can I switch to synthetic oil?

[99pathy]

I have a 99 pathfinder with 250000kms. I'm the second owner I believe it has conventional 5w30 in it now (this is my first oil change since getting the truck) I want to switch to synthetic. Would it cause any damage? Will my truck run poorly? Should I do half synthetic rather then full synthetic blend? Will I get a hp gain? Better startups? Faster warming up? (live in Canada -20c average winter) will my truck run smoother?

Or Is it really just not worth the extra $20 for 4qts

[ARKQX33V6]

At 250,000km synthetics may or may not work. If your engine is sludged up, synthetics will cause this crap to loosen up and travel around within the pathways and possible cause blockages elsewhere or block the oil filter. You may want to purge the engine with a solvent at a station that does this.

If you know what oil was used keep with it. If you want to experiment with synthetics do so but watch your oil pressures by installing a real pressure gauge and see what happens. Or just live with dyno oils and change often.

[miamiheat3332]

Id say go with doing half syn now, then when its time for yet the next one , do full syn.

[TheITsimon]

Synthetic oil lubricates differently than regular oil, to elaborate just a tiny bit more on ARKQX33V6's post.

Petroleum oil is not as fine as synthetic, as long as all your engine seals and gaskets are in good condition they shouldn't be any issues (meaning leaks), however in high milage vehicles get the high milage synthetic if switching. otherwise the space that the normal oil was not leaking through synthetic might.

the operating temperature of synthetic oil will be lower, not much but will be lower than regular oil, which contributes to longer engine life.

about cold weather and performance
here is an extract from http://www.ehow.com/about_5171570_synth ... tages.html

Synthetic oil offers a number of additional advantages. Synthetic oil does not lose its ability to flow well in cold weather, so it is preferred for cars driven in cold climates. Synthetic oils also perform better and more consistently at high temperatures, and so are frequently recommended for high-performance engines. Their chemical stability makes them less prone to long-term changes in viscosity due to temperature or contamination.
The net result of all of these advantages is superior lubrication of the engine. This can result in longer engine life, better fuel efficiency and smoother operation.

[fleurys]

The previous owner got 250,000km out of the engine with conventional oil.... here's your answer.... why spend more or change a winning combination..? you have nothing to win really...only to lose... a good old oil change every 5000km will get you far... your pathfinder ain't a ferrari.... hahaha

[Ammi]

You can go at least 5k miles easily w/ synthetic and good filter.

[740fizza]

Unless a car really calls for it, I don't usually bother. In my other car, it's had synthetic run through since day one and I go a year or 15k between oil changes. In this case it's actually cheaper to use synthetic since 8 quarts are used and a filter is $15-20. In the Q, I thought about it but not sure if the filter will last 15k miles so just stuck with dino. And to those who say change syntetic after 5k miles don't know what they are talking about. It's a waste of time. And no, I have no sludge to speak of since when I pulled the valve covers, everything was shiny clean

[alexf20c]

The VG33E does not need synthetic oil.

I have 180k miles on mine (or about 290k in Canadian talk) and I go 10k km in between oil changes, and I use dino oil. Motor still runs like a champ.

But if you want to throw away your cash...