Gr III oils for 10k miles?

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Would Valvoline SynPower hold up for 10K miles? I would feel more comfortable with something like a Gr IV/V blend but I'm quite uneasy with the GrIII for extended drains. Is it safe?
 
the car is a 95 Probe GT (2.5V6) mix of short and long trips and a good amount of hard driving. Basic bolt-on mods... your thoughts?
 
the_oil_dealer,

Check the used oil analysis Section for Castrol Syntec (Gr III) not the GC,
someone has run this oil many times for 10,000 miles with good results in a Chevy Metro or Suziki Swift,
but as the others have mentioned, it would be best to perform a oil analysis at around 7,000 miles and go from there.
 
I won't run group IV oils for 10K.

Your vehicle is old. If it's dirty inside, synthetics will loosen that filth & make matters worse.

If your engine is relatively clean, then try it for 7K max.

Just my opinion.
 
I bet that after 6-7k miles your HLAs would start ticking like crazy, that is assuming that they aren't all ready. Not b/c of the synpower, but b/c they become clogged easily and like clean oil.

The 2.5L Mazda KL is a great engine, but I don't think it likes extended drains. My $.02
 
IMHO, yes but only if it's an A3 gr.III ie. 5-40, 10-40 or 5-50. They are robust enough and my oil looked much better when I did 10k OCI's with BMW 5-40 (Valv. syth) than their replacement 5-30. Both are gr. III.

And look up Mori's 122k Audi with 10k OCI's on Syntec 5-50. Spotless....
 
10K could not really be considered an "extended" drain anymore. It's more like a borderline.
Especially on a newer engine, which is used mostly for freeway trips.
Todays group III syntetics are complex blends and utilize group IV or even group V components.
But it's always wise to establish a base line through an oil analysis since no one has the same engine conditions and driving environment.
Of course there will always be those who never go bejond 3K mile intervals no matter what.
 
I'd advise against it. I know, you hear all of the usual stuff about oils being better, and the 'freeway miles being easy on a car hype'. But extremely hot summers, air conditioning usage, multi-passenger loaded cars crawling along the freeway with minimal aiflow thru the radiator wouldn't make me comfortable with 10k mile or more oil changes! No reason to chance it.

Just get a good Group III or better yet a good group IV or higher oil ON SALE and run it instead to about 7k. Besides, just because your oil analysis comes back and says the oil is 'okay', who's to say how rapidly that it goes from 'ok' or marginal to no good? Good oil, changed before it reaches it's end point, is cheap insurance.

1995 Saab 900S; 202,900 original owner miles; orignal head, valves, pistons, etc, etc, etc. with no oil burning whatsoever.

IMHO
 
quote:

Originally posted by axjohn:
'freeway miles being easy on a car hype'.

Freeway easy miles are not a hype.
It's a fact.
What you've just described is called a stop-n-go condition, which is not usually reffered to as "freeway" driving, at least not on this board.
 
BTW, the term "cheap insurance" should be banned from this board, IMHO.
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If you're so cautious then just change oil every 3K miles and forget about this discussion, or any other oil related topics among with oil analysis and filter discussions.
The oil longevity shall never cross you mind.
But this is not what this board is all about.
 
axjohn

Idling and whatnot in the heat of the summer doesn't stress your oil from a temperature standpoint. It's always lower then with the same ambient temp at highway speeds. I've studied this very carefully and for a relatively long time. I've been doing 70mph with a 210-220F oil temp and began coasting off the highway on the offramp and watched as the temp immediately starts clicking down ...round the cloverleaf and back on the 4 lane and watched it ramp right back up to the former temp again. I've done in city traffic watching the same thing. It's higher (maybe-depending) then 35-45 mph driving ..but not as high as pushing a car @65-70 mph where the combustion input is the highest it will be per minute ..where exhaust temperature egress is at higher backpressure ..and the rad rejection is most stressed. This sends more stuff out through the pistons and whatnot in btu throughput. The only higher oil temp condition then highway, in my observations, is WOT in terms of peak temps.

So I think your concern over oil temps is unfounded. Sure you can have oxidation issues ..but they are usually trumped by fuel and other stuff before they're thermally shot. It's usually the insult associated with the warmup cycle that makes you need to change the oil. I do everything I can to get my oil temps up to 100C/212F+/- as soon as possible. I don't like paying for fuel to pump them when they're thick. A 20F swing either way isn't going to alter the life span enough to measure, imo
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Naturally, YMMV
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quote:

Is it safe?

Just don't be in a dentists chair if he's asking that question.
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If you would feel better with a Group IV ..then why not use one? I feel better when I take my medication regularly...so that's what I do (I'M JUST KIDDING - odd attitude morning
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).

I don't know your Mazda based engine's idiosynchracies ..but there's plenty of GIII oils that routinely make 10k PLUS without problems. It's just a matter of finding one that endures your abuse
dunno.gif
 
"What you've just described is called a stop-n-go condition, which is not usually reffered to as "freeway" driving, at least not on this board."

Maybe I misspoke; I assume "freeway driving" is supposed to actually mean 'highway speeds' on the freeway.

I don't know where in SoCal you are Vad, but out in my neck of the woods theres a lot less 'highway speeds' than 'freeway crawling'. I still think that actually driving at 60 or 70 on the freeway is a lot less stressful on an oil than doing 0 to 15 or 20, with lots of stretchs of not moving. In 100 degree ambient temps; with air conditioning on, etc. I just think that that is an extreme condition, so why take oil to 10 or 15k when oil is this ****ed cheap. And regardless of what some say, oil IS cheap insurance, or people on this board wouldn't be trying to get the best of it for a decent price/performance ratio.

And if you read my post there was no mention of a 3k oil change interval anywhere in it. EOM.
 
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