best motor oil for 91 Mazda 626?

hal

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393
Location
NC
has 2.2L F2 (non-turbo) engine. the manual is unavailable, ive checked some mazda forums and some people are using 5w40, some 10w30, and so on, generally a 30 or 40-weight. the car uses a little oil but not too bad, and has 164k miles on it. can anyone recommend a good brand and viscosity for this engine? (kinda looking for the reasoning behind your choice also) thanks!
 
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2,601
Location
Kansas City
I'd use Maxlife 5w-30. Might help with that oil use issue, may not either. But you will be conditioning the various seals, and it has a higher level of detergents for cleaning than standard oils. It is a great oil for older engines that has proven itself to many members on this board.
 

hal

Thread starter
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393
Location
NC
not a bad idea. ive used maxlife a lot, good oil. did not know about the amount of detergents it has, though
 
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38
Location
USA
I have a '92 Mazda MX-3 with the 1.6L B6 engine. It has 132K on the clock. I have had very good luck with 10W30 Castrol High Mileage in it. Initially I was putting Pennzoil 10W30 in it, and didn't really have a problem with it. Castrol HM was on sale at 'da Mart one day so I figured I would give it a try. The engine "seemed" to run smoother and even picked up about 1MPG. Whatever you choose I am sure it will be fine as long as it is changed out regularly. Every Mazda I have had ran great for a long time (except my '96 Millenia S - stupid Supercharger seals), as long as I changed the oil every 4-5K. 3K with city driving.
 

hal

Thread starter
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393
Location
NC
i have yet to 'test' this motor to the extent that i would like to. i gotta get the maintenance up and done first. i have heard about cylinder head problems, although seems like it is not too common. but it sounds good, seems like a good motor. i will prob. go with maxlife based on recommendations and good results in the past. i don't wanna put too expensive an oil into a car I paid next to nothing for.
 
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38
Location
USA
Would this engine be a good experiment for AutoRx? Since the car sounds like it is a bit of a beater for ya, might be a good test. If it was abused so bad that a simple spark plug wire change got it running again, one can assume that the oil changes were probably also few and far between.
 
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1,087
Location
Germantown TN 38138
Since you asked for the best, not necessarily the cheapest, my vote goes for Mobil 1 HM 10W30 for this engine. It is still an SL formulation, not an energy conserving oil, and should be very robust.
 

hal

Thread starter
Messages
393
Location
NC
it wasn't abused. the oil was clean and the ATF was not bad either. the guy took care of the car he just said he didn't want to get into fixing it. he knew nothing about cars, and a mechanic told him the missing was due to low compression when actually it was just a plug wire. [censored] untrustworthy mechanic. he said he had the oil changed about every 5k (and has records!). only thing im not too sure about is the timing belt, so i gotta remove the cover and look it over. im a little weary of auto-rx and other flushes. concerned that A. it might free up gunk somewhere and gunk something else up or B. make little external seal leaks worse. would it even be necessary w/ 5k oci's?
 
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6,156
Location
Buffalo, NY
I'd definitely think about doing the timing-belt... Any SM rated oil would do. If it doesn't use much, I'd stick with 10W-30 in warmer months, and 5W-30 in the cold ones. MaxLife is a great oil if bought on sale, but any conventional will do. As for ARX being a "flush," it isn't. It is designed to gradually clean with the oil over time and not a shock treatment like a flush. You might have as much luck with Rislone Engine Treatment or CD2 oil detergent added at the next change if you don't want to spend that much on ARX...
 
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691
Location
Aridzona
Give the valve gear a look, and go from there. Unless the car has developed a sludge problem, just about any decent oil, from raw dino juice to Redline's GrpV uberlube will do fine. If there is goo, the various synthetics are supposed (?) to be a little better at cleaning; I'd go with whatever 5/10W-30 is on sale. Run the cheap syn for a short interval, then check your progress. If the crank or cam seals are leaking, it can't hurt to try a high mileage mix. I'm kinda surprised to see all the Maxlife faithful jumping up and down. There are plenty of options. If the oil is being burnt, I'd follow 1999's advice and choose a thicker xW-30, or jump to an xW-40 mix. M1 High Mileage would be great, as would GC, or any one of a dozen other thicker oils. In short, pick something decent and don't worry about it!
 
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1,346
Location
Texas
I owned two of those cars (one turbo one non) and they both loved 10w30 and 15w-40 oils depending on the season. If you had the manual it would show you the sliding scale of oil weights depending on weather.
 

hal

Thread starter
Messages
393
Location
NC
this information is very useful, thank you all. does rotella synthetic 15w40 (or 5w40) have a decent amount of detergents? i took off the rocker cover when i was checking the timing belt today and it's not sludgy, but it's got a decent amount of varnish.
 
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703
Location
Northwest Indiana
 Originally Posted By: hal
this information is very useful, thank you all. does rotella synthetic 15w40 (or 5w40) have a decent amount of detergents? i took off the rocker cover when i was checking the timing belt today and it's not sludgy, but it's got a decent amount of varnish.
HDEOs like Rotella 15w40 and 5w40 should work great in your engine if you decide to go that route.
 

hal

Thread starter
Messages
393
Location
NC
im tempted. im pretty sure the motor is spec'd for an Xw40 weight as well. and considering its age it might be of benefit. i mean if it works in a hard-working diesel engine then it should be great for a 4-banger with 164k miles. now im torn. i know maxlife is good also.
 
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