At 200,000 miles I switched to 0w 30 synthetic in my vx, it's oil leavle drops less then a quart every 10,000 miles, it is concidered to be "acceptable" to see oil leavle drop a quart between 7,500 mile oil changes, so befor you switch to a synthetic I would first check your compression, and look at the bottem of the engine for oil drips, and establish a base line of how much oil is uses, if you leave a sheat of cardboard under the car over night, and it doesn't have oil drips on it in the morning, and your compression is up to where it's suposed to be, then go for it.
I put Mobil clean high mileage 10w30 in my car, and it burned, or leaked 2 quarts in ~4000 miles. I switched back to Castrol GTX 10w30. With Castrol it only uses about 1/2 a quart in ~4000 miles. I am trying not to offset my savings by using more oil, at a higher cost per quart. I will switch to 5w30 tho. So as usual, YMMV!
Just curious, because the high detergent action in synthetic forced the oil right past the seals on my protege and onto the driveway when I tried to use it.
I don't care what anyone says. I will always proceed with caution on an older car.
IMHO the switch-over time is the most painful time for a high-mileage vehicle. I found both my 91 CRX and my wife's 94 Civic leaked a LOT (maybe 1qt every 1000 miles) right after the switchover. However, that leaking tended to go away on it's own (over a few thousand miles of driving), as the synthetic worked to clean the crud out of the engine. That's why I just kept adding "makeup oil" and keeping my oil change intervals "short", until the car got used to the synthetic.
However, if I had to do it over again (knowing what I know now), I would probably arrange to clean the crud out of the engine first, using something like Auto-RX ( http://www.auto-rx.com/ ), and only after the engine was cleaned switch over to synthetic. Since most of the problems with the dino to synthetic cut-over are due to built up sludge and other crud, than (chemically) cleaning the engine first (with a slow "gentle" cleaner), should side-step many of the problems/risks of converting a high mileage car to synthetic.
Originally Posted by jj94auto
What do you all think of using 0w-20? I notice that some of the newer cars use that for better fuel efficiency. What about in an older car?
As I understand it, 0w20 is a 2-edged sword. It can save a little on FE, but that oil is a lot closer to being too thin (for proper engine protection) than say a good 5w30 is. And since 0w20 is "riding the edge" closer than almost any other oil, it takes much less to push that oil "over the edge" as it were (and therefore have yourself in a situation where your oil isn't protecting the engine enough). And there are a LOT of things that can degrade an oil's effectiveness (including just a varnished up older engine, since engine varnish interferes some with the ability of the oil to do its job). And in the case of a 0w20 oil (which is already "riding that line" closer than most oil weights), those factors could easily be enough to push things "over that line" if you aren't careful...
That's why my personal theory is that you should "proceed with caution", when using a 0w20 on an older car (that was never speced for it). Here's how I would proceed, if it was my vehicle:
1) First clean the engine, using a gentle cleaner. I've had good results with "Auto-RX" ( http://www.auto-rx.com ), and others on the "Bob Is the Oil Guy" forums also seem to like that cleaner. It's a little more expensive than some cleaners, and it also works slower than some cleaners. However, unlike a lot of cleaners, it seems to clean gently while continuing to lubricate the engine (and protect the engine against damage during the actual cleaning process). By cleaning the engine first, you help remove the problem of a dirty engine interfering with any oil you use (and often a cleaner engine leaks less oil as well)!
2) After the engine is clean, switch to a good Xw30 synthetic. My current favorite is Amsoil's TSO 0w30 (as it seems to be a very high quality long life synthetic, that is also rated for good fuel economy). However, that's clearly not the cheapest synthetic on the market (although I am an Amsoil dealer, so if any gassavers members want to PM me, I'll be happy to arrange some discounts). And even a 10w30 synthetic is probably better than 10w30 dino oil (although you will often get slightly better FE with a 5w or a 0w oil, than with a 10w oil).
3) Monitor how the engine is doing on the Xw30 synthetic. Until/unless the car is handling the Xw30 synthetic well (including low loss of oil), do not go any further. However, with luck, the car will get used to the xW30 synthetic reasonably quickly.
NOTE: A good "fuel saving" 0w30 synthetic can be used safely in virtually all cars originally speced for either a 5w30 or a 10w30 (as the 0w part is just how easy the oil flows when COLD, the w30 part is the normal "hot" thickness, and in most cases it's better for both the engine and FE if your oil is very thin at initial cold startup). And using something like the Amsoil TSO 0w30 I like, should still save some fuel vs a normal dino 5w30 or 10w30 (not as much fuel savings as a 0w20 would, but still a saving over a more traditional oil), while still being well within the "warmed up" tolerances of a 10w30 oil (so a 0w30 synthetic is actually a very conservative/safe oil to use in most cars)!
4) At this point, when the car is handling the synthetic Xw30 (ideally a 0w30 synthetic, for reasons mentioned above), it is now reasonable to start experimenting with adding a little 0w20 synthetic into the mix (ideally from the same company making your 0w30 synthetic, so as to avoid possible chemistry clashes between the two oils). You should then monitor the effect (for both positives and negatives) closely. And as part of that monitoring process, it probably would be a good idea to spend $20 or so for a chemical "Used Oil Analysis" (to get some lab results as to how well your engine is handling the oil mix).
5) Assuming that you don't have extra problems (such as too much engine wear showing up in the lab's UOA report), than you can up the percentage of 0w20 in the mix for the next oil change, and again monitor how the engine is handling things. Assuming everything works fine, you can keep upping the percentage of 0w20 in the mix, until you either find that the engine handles it worse (in which case back off to what the engine likes) or you are now running 100% 0w20 in your car.
If you are wondering, I'm currently at step #4 in this process. My car currently has 1 quart of Amsoil synthetic 0w20, with the rest of the oil being the Amsoil TSO 0w30. And even with only 1 quart of 0w20, I notice some positive engine effects vs just the 0w30. However, my wife's Civic still has all 0w30 in it (as Amsoil's 0w20 wasn't quite on the market, at the time my wife's car got her last oil change), and so I also know that even the 0w30 seems better (from a friction/smoothness standpoint) than the Mobil-1 5w30 that I was previously using in her car (and likewise the Mobil-1 was better than the normal "dino oil" that proceeded it)!
So while I'm expecting to be able to reliably go with a 0w20/0w30 oil mix in my cars (the big question is how much 0w20 in the mix gets me to "the sweet spot"), I would still be way ahead of most oils even if I were to just go with the high end 0w30 synthetic (and not add any 0w20 into the mix).