I did a search and found plenty of discussion about miles between changes but I average about 500 miles per month so I currently change out my Mobil 1 based on time, about every six months.

90% of my driving is (obviously) short trips and we were told back in the stone age that short trips form acids and carbon and other nasty stuff but what is the current thinking with modern engines and synthetic oils?

Should I rethink my timing?

 

Carver, thats 3,000 mile oil changes your doing? I`d reset the maint. required light when you change the oil, and just go 5,000 miles. You`ll be fine. (especially on the synthetic) I would only do 3,000 on conventional oil. (I know they say dino can go more) But I just dont trust that in these MZ motors.

 

I use semi-synthetic Valvoline Durablend @ every 3,000 miles and my car loves me. LOL

 

Thats good stuff.

 

10K if you change your filter at 5-6

 

I might or might not have went 18K on a single oil change of Mobil 1 High Mileage full synthetic. The tech that changed my oil reported it was a little dark, but otherwise no harm done. I'm approaching 7K since my last change, which has been largely highway, but with the 150K maintenance coming up, I might as well change it now.

 

I agree with your observations regarding short trips.

You could go longer on your oil changes, however, why risk your engine if you plan on holding on to your vehicle for years to come?

I change every 6 months with 5W30 Mobil 1. Usually less than 5K miles between changes. Only time I make a change is when I go on one of my trips up north. Those trips usually account for 3000+ miles by the time I am done. Then, I will adjust as needed doing a change early before the trip or extending past 5K miles when I return.

If I was putting more miles on the vehicle (say 15K per year) and being as easy as I am on my RX330 I might go 7500 miles between changes if I was running Mobil 1 and not feel guilty. Would still come out to an oil change every six months. I average 10K miles per year so I average 2 oil changes a year.

BTW, I use NAPA Gold oil filters made by WIX. You can still get the old (original) extended oil filter over the newer shortened version if you ask.

Of course, YMMV.

 

Just wanted to add that with today's fuels you get less contaminants in the combustion process and with tighter engine tolerances you get less blow-by the piston rings. So, 5K on regular "dino" oil in the crankcase giving little problem gives you an idea of what the extra protection synthetic provides.

If times were tight here I might even cut back to one oil change per year. But at the moment there is no need.

 

if you use mobile 1 it says 6,000 miles or about 6 months not sure with any other brand....

 

For those following this thread...

If you are a Mobil 1 user and...
if you shop at AutoZone...
this coupon may be of interest to you.

http://www.autozone.com/images/MEDIA...onLPcoupon.pdf

 

The new RX's call for sythentic at 10k intervals. And uses the same oil filter as the 2nd Gen RX's that call for dino oil every 5k. Just food for thought.

 

When I bought my RX two years ago now, I pulled the dipstick out, and there was that dreaded baked on oil stain stuff. The first owner did all oil changes @ Thompson Lexus (where she bought it). Which is a good thing. She went 5to 7k oci`s.My first change I put in pyb, then went to Mobil-1 0W30. the motor made all kinds of weird noises when cold. Judging from the way it acted,and the stain on the dipstick, I think this motor was heavily varnished. And every time I change the oil,its always very dark.My point is, the MZ motors have pretty high oil temps, and I think 5k (at least on dealer bulk oil) was kicking the oils *** bigtime. Thats the only reason I wouldnt go more than 3-4k on Dino. (on the 3MZ-FE anyway) which is still a better motor than the 1MZ-FE,as far as oil passages etc.

 

Good point regarding the new models. Still, there are enough changes in the MZ engine of late with cylinder coatings and such that I would not apply those capabilities to a prior year RX350 let alone what Carver and I have with our RX330 engines.

Keep in mind that JiffyLube recently announced there was no need for 3K mile oil changes.

http://www.nytimes.com/2010/09/11/yo...shortcuts.html

For drivers like Carver and I it is more about time than miles.

 

Well, doesn't look like there's any reason to change my schedule. I consider Texas weather to be "severe service" so every six months it is.

 

Carver I do every 5K but don't rush it when the light comes on