I'm planning to go bring my car in for an oil change later on today. Previous owner had been using Mobil Super 5w-30. I want to go with something better that I can trust like Mobil 1 synthetic, so I'll be bringing in 4 quartz and an oil filter. I was wondering if that's all I'll need to do. Would I need to get the system cleaned out before going with a different brand or would it just be the simple process of draining out the oil and topping the engine off along with a new filter?

These are the oil and filter the previous owner used: Buy Mobil Super 5W-30 5000 Conventional Motor Oil (1 qt.) 98HC44 at Advance Auto Parts

 

Last I've heard most people say to avoid Mobil 1 synthetic but I can't remember why. Also, you should stick to conventional oil unless Royal Purple Synthyetic or Idemitsu. Even builders like RotaryEvolution say to not waste the money.

 

Sounds good. I'll be sticking with conventional oil since this car is my daily driver, and not for racing. I'm in Sacramento, California and was wondering if 10w30 is good enough or is there a better recommendation? I remember posting in one of the thread in August and someone said I just lowered the engine life by half. Not sure if he was kidding or not.

Edit: I found out in the old post that I used mobil 1 synthetic 10w30 at that time lol

 

On the owners manual it says 5w30 for colder temperatures. I'd go with the 10w30 assuming you're driving an N/A, right?

 

Yup mine is N/A

 

the Mobil 5000 isn't a synthetic blend at all and the 5W-30 is a little too thin for a rotary engine, even in the tighter tolerance renesis engines they were seeing excessive rotating assembly bearing wear from the lighter weight oils.

10W-30 is the lightest weight you should EVER run in a rotary engine even in winter.

 

i saw another post about a guy using castrol gtx 10w40. i took a look at walmart and they have a 5quartz jug of the castrol gtx for $15.97. will the 10w40 be good enough?

 

if the engine isn't old and tired 10W40 is fine. when oil consumption and low pressures are noted then thicker oils should be used.

 

20w50

 

20w50 has my vote. hmmm well depending on season and engine condition

 

hmm my engine seems to be in great condition. i can go to 8k-9k without any hesitation. it has also been my daily driver. the previous owner said he rebuilt the motor with his friend 30k ago. not sure if it's true or not since there wasn't any paperwork, but i've driven it to san francisco and los angeles a few times back and forth before. i got the car from socal as well.

 

I don't trust Mobil One because Mobil refuses to specify whether it is made with real synthetic base stock (Group IV or Group V) or whether it is made with bullshit synthetic base stock (Group III). Unfortunately, the FTC has ruled that oil companies can call Group III "synthetic", even though it isn't.
https://www.mobiloil.com/USA-English...Base_Oils.aspx

Anyway, Mobil does not recommend using their synthetic oil in rotary engines.
https://www.mobiloil.com/USA-English...ry_Engine.aspx

Also, Mobil One transmission fluid has been known to eat the synchros in the RX-7's transmission. Supposedly Mobil changed the formula, but I still don't trust them. There are plenty of other good brands to choose from.

I agree. Synthetic engine oil is a waste of money unless the car is used on the race track or in extreme hot or cold weather conditions.

I use Castrol GTX 10W-40 because it works great in both Summer and Winter here in St. Louis. In Florida I used the heavier Castrol GTX 20W-50 because of the warmer weather.

10W-40 is already pretty thick. Going into October, I think that 20W-50 would cause unnecessary wear during cold weather start-ups. If the engine is blowing oil then he can add more oil periodically and avoid downshifting until the engine is rebuilt.

 

Make sure the filter is tight and the oil drain plug is tight. I always do my own because I know multiple people that blew their car up down the street from leaving jiffy lubes. It's not hard to do yourself, and if you have an rx7- you should be used to playing with oil anyways.

 

Let me cut to the chase for you:

California weather, 20-50 year round, but 10-30 would be the second choice.

Elsewhere across the country where weather temps are more extreme (especially in the northern states), 10-30 would propbably be the first choice, 5-30 a fair second choice.

Most synthetics these days would be fine. But as pointed out, the way rotary engines use oil a bit wasted expense since you need to change the oil just as regularly as you do with dino oil. The sales pitch that you can go longer between oil changes with synthetics does not apply to our engines.

On a personal note, recognizing the superior lubrication aspects of synthetic, I tend to use a Synthetic blend.

More over, given the increase in the wholesale price of oil, the difference in cost between synthetic and dino has compressed considerably. I've had times during odd sales promotions where the cost of a synthetic was about the same as dino, so synthetic is what I bought.

Bottom line, so long as you're going with major name brands, I suggest you can go with what ever is on sale. But go with 20-50 so long as you're in the great state of Califonicationia

Sidebar, since you gave the question but didn't ask, WIX filters are excellent filters. Filters can be just as important a choice as what flavor oil you use. Of you use the rx7club.com search engine, you'll find discussion on filters and links to web sites that present in depth analysis of the various brand options and related merits.

 

Wix 51344 is an oversize filter, perhaps the largest diameter and height that fits the oem oil pedestal location. I buy them and use them for my 90 vert. Might not fit on the Turbo, don't know yet.

 

i decided to go with castrol gtx 20w50. it's blazing hot up here in the valley of california, and i believe that it's going to stay this way for another month or two. thanks guys!

 

It sorta pissed me off when Mazda did an oil change without asking me when they fixed my starting issues. They also put 5w30 when the manual says 10w30.

 

..and you wonder Why people work on these cars themselves and call it the "stealership"??.
If I ever take my car to an Oil change place or get the car serviced at Mazda,then I would be typing replies from a Mental Facility...and they don't have a 'Location Icon " for that!
..10w30 used in my car.Canadian weather.No winter driving.Summer only.

 

I live in Vancouver, BC, Canada and I use Castrol GTX 20w50 till November, then it's Castrol GTX 10w30.

Oil change intervals every 3000kms including OEM Mazda Oil Filter.

 

so 20w50 works good in the valley? i commute with my 7 as well. i put 120+ MILES on her daily. from stockton to fremont. thanks.

 

If they got your car to start when it was severely flooded than doing an oil change is warranted. Its not uncommon for a flooded engine to have washed out oil(fuel contaminated), that alone will do more damage than having lighter weight oil in the car.

 

guys, could my car be overheating because i switched to 20w50? i just changed my oil on monday and now my buzzer is going off and over heating. any ideas?

 

Thanks, I enjoyed that laugh.

NO, 20/50 would not cause your engine to over heat, certainly not to a point where warning buzzers would be set off.

Something else simply happened in the course of doing your oil change.

 

I rock mobil1 15w50 and mazda factory oil filters, but my OMP is fully removed and I run 2 stroke pre-mix.


why would you pay someone to change your oil? I can change mine without even jacking the car up, and most service places will take your used oil free of charge

 

i was too lazy to change it myself. i would also need a jack cos my car is low