Can't decide between 10W-30/40 and synthetic/dino..

[islandboy57]

Looking for some advice/comments since you guys know the 1MZ the best!

- 84,000 miles
- almost exclusively short city trips (5-10 minutes)
- slight oil leak (and it might be burning a bit of oil in conjunction with the slow leak) = 1/4qt per 3 months
- currently using Valvoline MaxLife 10W-40 synthetic blend
- fuel economy averages 15 MPG 100% city
- temps stay in the 80s year round, 90s during the summer

What do you guys think? I use 5W-30 Valvoline SynPower in my gen 5.5 and like it a lot, much better than Mobil1 which I used before. I'm thinking about using 10W-30 SynPower or even 10W-40 if I can find it. I'd like to use 10W-30 for the sake of fuel economy but am wondering if 10W-40 is better anyway.

Just looking for comments. I'm going to do an oil change tomorrow.. I do it every 3 months if I have time, I figure it can't hurt with all that city driving.

[ToRn]

Not much difference at all, go 30 if it's cold most of the time where you live and go 40 if it's warmer where you live.

[Stillrunning]

A thicker oil does not necessarily mean better lubrication or protection. I tried Mobil1 0w-40 in my Camry and it definately affected start-up lubrication as you could hear the engine struggle a little before full idle. Oil analysis was not too bad but not great. I switched to Mobil1 0w-30 and it is much better on start-up with an improved analysis report. If you don't do used oil analysis you don't have a clue about what's working the best. I'd pick the lowest grade possible to give good start-up lubrication.

[FireFire]

no need to use synthetic. just change the oil every 3k~4k instead of 5k. cheaper and good for your camry.