I have a '91 Xterra 4x2, bought new in October '00, with a little over 92,000 miles. I currently run Pennzoil 5w-30 but am considering a change to a synthetic oil because of mileage. Any suggestions?

I didn't see a significant change in milage after I changed to synthetic. Driving style and speed contribute more than anything (of course no one wants to hear that )

EDIT: There is no need to post in more than one forum either - mods will move it if they need to...

In theory Synthetic will improve your mileage, but the reality is that it's not a noticeable difference. We're talking fractions of a MPG at best. Getting better gas mileage is NOT a reason to switch. Being able to extend your drain intervals and provide better extreme high and low temperature protection IS a good reason to switch. I'll be the first to admit that regular oil changed on a reasonable schedule is perfectly good for the Xterra, but my Xterra works hard in temps over 100 degrees in the summer, it has to start at 30 below in the winter, and I don't like throwing out oil (yes, I actually recycle, but...) all the time. Synthetic provides the protection and the extended drain intervals that I demand. That's why I use it; not for a mileage increase.

BTW, where did you find a '91 Xterra? :p

OK I'll ask 91 Xterra???? Typo I guess?

Possibly he means pathfinder?? If that's the case you on the wrong website

i got a 2000 X-terra with about 30 000 km on it, and im running on castrol synthetic 4x4 10w30 oil with the fram double guard oil filter, i switched to this oil like a month ago, there is a little difference then before, but with gas being about 90 cents a litre it was worth it.

Sorry ... it was one of those days and it is an '01. Not looking for mileage, but for doing whatever I can to extend the life of the engine ... have changed oil on a regular basis from day one and enjoy my Xterra and want to try and make it last.

Thanks.

From what I have been told, not much point in putting synthetic at such a high mileage. That comes from my dad who is a fleet forman for the state power utility. The best thing you can do to extend the life of your engine is to keep up on the oil changes, and do the timing belt/water pump/etc at 105k.