Changing Oil Type...but Not Filter? (Mazda6s)

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Sep 25, 2002
Loveland, Colorado
Hi crossbow, welcome to the group! I haven't been following the xW-20 threads 'cuz I don't expect to ever use this wt. (If I had a car that called for it, I'd probably pick a lighter 0W-30.) So please forgive my ignorance on some of the details you've alluded to. I have some questions for you: 1) can you summarize the comments (in the various threads you've read) that made you decide to go back to xW-20? 2) how often will you normally be changing the oil & filter? Thanks for the add'l info! -Greg
Hey Eiron, Do note that I'm a n00b at this. First off the main reason I'm doing this, is because its a brand spanking new car thats under the 5w-20 requirement...not an older model car that was recently switched from 5w-30 to 5w-20. This of course could actually mean the mazda internals are actually designed for a lighter weigh oil. I didn't think anything of it till a fellow forum member switched from the 5w-30 he was running to 0w-20 and noticed a difference in how smoothly the engine rev'd. So I decided to begin reading on the various types and doing research. So here I am going to try 0w-20 for awhile and see if I notice a difference. Of note is, that both the Mobil1 5w-30 and 0w-20 both offer superior protection to the syn blend 5w-20's. The oil changes I'm doing are... At 1000 At 2000 At 5000 I changed the oil and filter at 1,000 and will be changing the filter again at 5,000, then every 5,000 from then. Then every 5,000 from there with a UOA at the 5k mark for the 0w-20. Of course if anyone who knows better has any suggestions, please bump in.
Greets, I'll get right to the point. My current car is a Mazda6s (2003) which requires 5w-20 oil (it uses the ford duratec 3.0 liter block and mazda internals). I recently changed the oil at a thousand miles to 5w-30 Mobil1 supersyn with a K&N HP-2010 Filter (Which fits fine, thanks for previous Mazda6 help!). However due to various discussions between 5w-30/5w-20/0w-20 syn on both this forum and the mazda6club forum, I've decided to swap out the mobil1 5w-30 for 0w-20. (Both Synthetic) The K&N Filter is only going to have about 2,000 miles on it when I drain the 5w-30 out. My questions are... 1) Should I replace the K&N filter now with the oil change (only 2k miles) or wait until 3k miles to swap it out (5k total on the filter). 2) If I'm not replacing the filter, should I still remove it and drain as much of the 5w-30 out as possible? Or will it be fine to just drain the oil out and do a refill with 0w-20? Thanks in advance for any assistance. This is my first new car so I'm unbelievably paranoid. My other car (which still runs) is a 74 grandam pontiac and I want to try and keep this one just as long [Smile] . Greg Hess [ July 03, 2003, 12:48 PM: Message edited by: crossbow ]
Hey crossbow, Yeah, trying to deal with the specifics of a warranty & figger out what the real motives are behind the requirements is tough to do. Your planned intervals sound good to me, especially with this new vis group. Just out of curiosity, what intervals does the manual call for? Since you've already admitted that you're "unbelievably paranoid" about this new car, getting everything outta there & starting fresh all around sounds like the safest course of action. (And never admit you used 5W-30 until you're OOW. [Embarrassed] [Big Grin] ) That way, there are no variables & no questions to bug you for the next 3k miles. If it were me, I'd leave the filter on w/o draining it & just replace what's in the sump. But then, it's not my car ... [Wink] -Greg
it would be a waste to swap out the oil filter at this point given the cost of those filters. Use it as long as possible, thus at least to 5000 mark. Do whatever you like with the oil, but I'd leave the filter and maximize its use. The small bit of 5w-30 will be a benefit more than anything. good luck Joey
Thanks for all your comments everyone. Its greatly appreciated. Eiron, Mazda USA is calling for a 7,500 mile change interval on 5w-20 blend. Whats really crazy is that ONLY Mazda USA is calling for such a huge interval. The european and oversea's markets have completely different service intervals, including an oil change at 1000 km. (600 miles) So regardless of what solution I end up choosing, I'll still be keeping the engine significantly cleaner and better maintained by changing out every 5k with a synthetic. As mentioned before I'm going with the 0w-20 for 3k miles more for curiosity then anything else. Other Mazda6 members have reported differences in engine reving/performance with the 0w-20 over the 5w-30. I'll end at 5k miles (on the odometer) with a UOA and make sure the 0w-20 is providing sufficent protection. Then I'll probably make a final decision to either go with 5w-30 mobil1 supersyn, or 0w-20 supersyth. Actually because of the 4th of July weekend, the 0w-20 was actually on sale [Smile] . Greg Hess ThirdEye Studios NYC
It should be mentioned in this thread that the manufacturer's recommendation for type oil to use is often based on CAFE (fuel mileage ) concerns, not longevity of the engine. Sure, they want the engine to last 36k for warranty purposes. But they are more concerned about the Corporate Ave. Fuel Economy ratings the products meet. That's why you have seen the manuf. recommending 5w/30 and now 0w/20. Cynical in South Carolina, Jim with 189,000+ on the 94 ImpSS
I'd relax if I were you. That car is so new, you have plenty of time to compare and test oil differences. And if this were my car, which it isn't, I'd leave the M1 5W30 in there. It's a fine oil with ONLY 2k miles on it, an expensive oil (expensive K&N too), and so close in viscosity to a 5W20 to begin with, that I truely wonder if you'll ever notice the difference. I have an Escape that's had both M1 5W30 and Castrol 5W20. Can't say as I've ever noticed a difference in engine reving as other Mazda6 owners have observed. They could be right. An Escape aint a Mazda6 either. But to your original that you said you're going to do a UOA at 5k, I'd suggest you change the filter. If not, I suspect that plenty of Mobil 1 oil will be left over in the existing filter to really influence the test results of the new 0W20 oil. If you want good results for comparison you want as little of the old oil in the test sample as you can get. Personally, I do a UOA on the 2nd change of a new oil just so I know I'm getting the best results on the current oil without the influence of any previous brew. You may also want to wait awhile on a UOA anyway. Again, that engine is so new it's really still breaking in. So be prepared for a lot of high wear numbers just because of that factor alone. My $.02 [Smile] [ July 05, 2003, 10:57 AM: Message edited by: Roger ]
Hey Roger, Thank you for your reply. Unfortuantly I had JUST drained the oil and replaced it with the 0w-20 while leaving the K&N filter in there. Dang it. So maybe what I'll do now is run this oil for another 3k (5k total on odometer) then change both the filter/oil (sticking with 0w-20) then do a UOA at the 10k odometer mark. Hows that sound? Ya Mobil1 and K&N's are expensive...but the amount I'm saving on gas alone allows me grand flexibility in my oil/filter choices. (My old vehicle...well still running secondary vehicle is a 1974 GrandAm Pontiac 6.5 Liter got around 8-12 car gets 24-28 hehe). Thanks again for all the comments and posts. I appreciate it. This site is an utter wealth of information. (Continues watching oil drain out of the pontiac). Greg Hess
Originally posted by crossbow: ... So regardless of what solution I end up choosing, I'll still be keeping the engine significantly cleaner and better maintained by changing out every 5k with a synthetic. ... ... So maybe what I'll do now is run this oil for another 3k (5k total on odometer) then change both the filter/oil (sticking with 0w-20) then do a UOA at the 10k odometer mark. ...
Yeah, I like these decisions too. Especially since JAMA doesn't think xW-20 wt oils offer adequate chain wear protection without enough phosphorous. Also, all of the M1 xW-30 wt oils are ACEA A5 rated, while the 0W-20 only meets A1 specs. I'm interested in what your initial impressions are since making the switch.
Erion, Though it may be placebo effect related... I've noticed the rpms don't drop as sharply with the 0w-20 as with the 5w-30. Probably just me though. I did some more airbox modifications to the Mazda6s during the 5w-30 to 0w-20 that could be related to it as well. I guess we'll just have to wait till I get a UOA in a few thousand miles.
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