I have 20w50 in my car now. I haven't driven it enough for it t need an oil change before it gets cold. It's going to get cold here soon. How long should I wait to change the oil to 10w30? or i mean what temerature do i need to change at? Will the heavier oil freeze or something if it gets too cold?

btw, someone told me that on rotaries, the seals stick to the sides in the winter. Is this true?

this is the first winter i've had a 7, and i don't want to mess it up.

 

I've never had a problem in winter... Oil doesn't really freeze btw, it just turns to this thinck syrup stuff that has poor heat capacity.

 

just warm it up once a week and you should be alright

 

If you have an owners manual it'll show the temp range of of oils, i would change the oil when the temp starts to hit around freezing. And no the seals wont stick in the winter.

 

that's what I thought. the guy that told me that was an older guy, and I told him I hadn't heard anything about sticking seals. He's probably thinking of when rotaries were first being developed. He knows a lot about cars, but not a lot about rotaries...rotarys...rotary engines.

 

what oil should you use during the winter? 10w30?

 

that's what I plan on using.

what happens if i don't change to a lighter weight oil? Would that cause damage to the engine or just run sluggish till it warms up?

 

I don't think it would that big of a difference but I''m doing it in hopes to relieve added stress on the engine?

 

20w50 is pretty thick at cold temps.
More oil will bypass the oil filter when cold.
Since regulators are PSI based and not flow based, more oil will be dumped until its warmed because of the resistance to flow.
And, thick oil robs power.

Drive gently until warmed up. This is why I like the e-shaft pellet mod.

Consider a 5w30 for improved cold weather flow. You can also run 5w30 or 10w30 year round.

And, since you should be changing your oil 4 times a year or every 3k miles. If you're oil weight brain washed, you can just match the oil weight with the expected average weather for the oil change interval.
For example:
Jan 1-- 5w30
Apr 1--10w40
July 1--20w50
Oct 1--10w40
Adjust the weights and dates for your location.

And, you wonder why I just run 5w40 year round.

I also don't see why 20w50 is so popular.

 

When I got my car, i think it had 10w30 in it. that was in july when it was 80-90 degrees outside everyday, so i replaced it with 20w50 and noticed a big difference.

 

The motor uses oil regularly if you still have the oil metering pump and your not using premix. Just add 10w 40 untill you need and oil change.

 

Welcome to the FAQ.

Oil won't freeze (at least at these temperatures), but it will... harden for lack of a better term, and not lubricate properly until it reaches a proper temperature.

Aka... bad for your engine.

 

So I don't have to change the oil completely to go to a different weight?
I thought that was bad.

 

Ive had my car for 7 years as a daily driver. It dosent hurt to replace the used oil with another grade as far as I kinow.

 

No, No and NO!

http://www.aaroncake.net/rx-7/storage.htm

 

Just get a decent HDEO 5w-40 and be done with all of the oil foolishness.

I don't buy the bull about feeling a difference when switching to 20w-50 oil other than it possibly feeling more sluggish. Only benefit of a 20w-50 weight oil is if you have poorly running engine with lots of blowby, fuel dilution will not hurt a 20w50 weight oil as much as a lower visc. range oil....e.g. a 20w-50 diluted to a 10w-40 will protect better than a 5w-20 diluted by fuel.


Oh, BTW, the sulfated ash issue with today's European Spec 5w-40 HDEOs is not relevent so please no outdated info showing that wider viscosity oils have higher sulfated ash levels.
Tighter specs and environmental regs demand less ash in oil so don't be scared to use a quality 5w-40

 

i think i noticed a difference with 20w50 because the previous oil (10w30) was too thin or whatver for the 80-90+ temperatures I was driving in when I changed it

 

^^^ Have you tried 10-40 oil? Also make sure your anti-freeze doesn't really freeze if where you live snows.

 

Not that it has anything to do with this thread, but I recently switched to 10w40. Seemed like a good compromise between 20w50 and 10w30. I wanted a thinner oil for when winter came but I also wanted it to act like a thicker oil once heated up. Many people don't like 10w40 because it takes more viscosity improvers to get the 40 top number but if you keep your oil changed as recomended I don't see it as a problem. Also on the chart in the FSM 10w30 is only good up to about 90 degrees where as 10w40 goes the from -20(same as 10w30) to the full upper range of the chart. This would make it appear that if one isn't seeing temps below -20 it would be the best choice for someone who wanted to run the same grade year round. The reason I posted is I thought the original poster may want to consider 10w40 instead of 10w30.

 

hmm.. i may try 10w40. I don't know much about oil except higher numbers=thicker and better for high temperatures, and castrol gtx is good.

 

I've been using 10W-40 in my RX-7's for 18 years, although I only put about 1000 miles a year on them, mostly summer. In the winter I pick a nice day a give it a good highway run about every 3 weeks.

I had a '79 RX7 that when bought had some coolant seal blowby at high RPM's when using 20W-50. I called Rotary Beat and they suggested 10W-40 to get some more life out of the engine. This was in 1988, I switched and the white smoke at high RPM's went away. Drove the car like that for 14 years with no noticable change until selling it to purchase my '88 vert.

I use Castrol GTX 10W-40 year round in New York City, oil looks new when drained, I've never worried about the wide viscosity issue concerns, only one change a year before winter.

 

well 10w40 it is then, thanks guys