what oil do i use in my t2 what is the best and what is the worst

 

There is a bunch of debate on that one. I use Castrol 20w50 in the summer and if we get a real cold snap in the winter I switch to Castrol 10w30.

 

IMO the best engine oil is one of the Group V synthetics, such as Red Line or Motul. The Group IV synthetics like Royal Purple and Amsoil also have merit. However these are too expensive to be practical in a simple street car that has a 3,000 to 5,000 mile oil change interval.

Most RX-7 owners use Castrol GTX. I have used it with good results for over 17 years.

I am happy to say that I have no idea which oil is the worst.

 

You'll have to make the decision by yourself as to which oil is best for your needs.

I suggest you visit www.bobistheoilguy.com and spend a couple of hours reading up on oils.

Castrol is a decent non-synthetic oil but Texaco Havoline Supreme seems to have a slightly better additive package. Mobil 1's 7500 oil appears to be a Group III oil and is priced slightly higher. Of course, you would not want to exceed a 5k oil change interval in a rotary.
Another Group III that I recommend and use is Shell Rotella T 5W-40. It says synthetic on the label but don't let that fool you, its a Group III basestock and is VERY shear stable and won't break down. It is a very high detergent oil and has a very high total base number (TBN) and could conceivably result in increased engine deposits when injected into the combustion chamber. I however, haven't had any problems yet with it and do believe in an Italian tuneup at least once a week to keep the carbon from gumming up the works.

 

It really depends on how much money you want to spend on oil.

 

Poor quality synthetics as you call them (Syntec, Penzoil, Havoline etc.) are not true synthetics. They are severely refined oils and are classified as Group III. They are much better than your regular non-"synthetic" Group I and Group II basestock oils.

I wish somone could prove to me the "ash" content of a motor oil that was not designed to be burned. Is it on the label?

 

Alot of controversy on the usage on synthetics. I had a friend that had a 85se and had over 200k on it and used very little oil between changes. Although he did start the car off on synthetic Amsoil after breakin period. royla purple from people i have spoken to is an excellent oil. If it is a older engine with miles on it i would not recommend going to synthetics. I personally run 20w50castrol year round. Have never had trouble with this.
Might want to see what is factory for the rx8? Synthetic or mineral? rx7doctor

 

I sugest in this order.
ELF, Red Line, Motul, Royal Purple, Mobile 1, Castrol GTX
I use RP 20W50 b/c I can get it localy. If I had to order and price was similar I would use RL.
I use 5W20 in my RX-8
can anyone exsplain how synthetics cool? considering that heat runs away from synthetic oil unlike conveshional that attracts heat??? Just food for thought
On second note when I was using synthetic in my yz250f "bike in avator" I was going through cranks in it like mad and $900 a pop gets price quick. Another friend I race with when racing arena cross said use Honda HP4 b/c he was having same problem and switched to the HP4 a synthetic blend and had no ishues and 2 years lattor I have yet to lose a crank.

 

was using castrol gtx 10w30 most year round

but ended up switching to 5w-20 mobil one during the winter and sometimes during summer as well as 5w-30 during the summer
no problems yet


and iceblue I don't think heat runs from synthetics think it is the synthetics just don't break down from heat as easily as dino **** does

 

i've used 10w-40 mobil 1 for 3 years and so far no problems

 

I use 10w30 (Either Non-synth Valvoline or Castrol GTX) year-round with mazda OEM filters.

-Andrew

 

Thread closed... subject covered so many times it hurts