rx7junkie170

I have a 12a streetport that I have been running synthetic royal purple 5w30 [winter here in NY ] . I was speaking to rotorheads and mostly all them was telling me that I'm wasting my money on that expensive oil, that all them run Castrol gtx on there street cars and some of them have 350hp turbo 2s so I went to Walmart and was gonna buy 4qts of 20w50 Castrol gtx they ain't have so I got 4qts of 10w40 regular dino Castrol gtx , the white bottle so I'm planning on changing my oil next week or so cause now the summer is coming and I dont want to run such a thin oil in the heat. will I have any issues with going from synthetic to dino ?, What do ya suggest should I switch to Castrol gtx or stay with the royal purple mobile 1 etc expensive oils ? I was planning on just running the Castrol gtx and swapping it out every 2500-3000 miles cause it wont last as long as a synthetic with out breaking up and thinining down I also run my stock omp pump and I was thinking that maybe the Castrol gtx might burn better then the royal purple in the housing while injecting the oil cause it's a dino oil so what you guys suggest ? Thanks its really a weekend car and when I take it out I do beat the crap out of it i also premix 1/2 oz of tcw3 2 cycle oil per gallon . I'm really here and there and I decided this would be the best people to ask about this decision am thinking of making. thanks guys

t_g_farrell

iTrader: (1)

I use the 20w50 Castrol and change my oil about every 3000 miles. By then I have added 1/2 to 3/4 a quart and its getting some gassy smell as well. You need more than 4 qts if you change the filter. I do a filter change every other oil change and use either the mobil 1 or K&N filters which are some of the best to use IMHO. Do not use FRAM whatever you do.

I also don't buy oil at Walmart anymore and prefer the oil from one of the B&M autoparts stores. My understanding is that for Walmart the oil is lower grade made special for Walmart because they can order such a huge volume. I just don't trust it anymore.

j9fd3s

iTrader: (3)

10w-40 is more than fine, you will want 5 quarts.

Ckforker

Why's everyone running such thick oil?? I must be missing something, I've been running 10/30 in mine since I got it. I'd think heavier oil would zap a little horsepower and mpg.

Granted, I'm in the mid-Atlantic area so it's not hot like out west.

t_g_farrell

iTrader: (1)

20w50 is the recommended weight for up to 120F. 10w30 is good to 85F. You can get away with the 30 but 50 is safer.

JOE68

i use 4 quarts 20w50 Castrol and 1 quart lucas..https://lucasoil.com/products/engine...oil-stabilizer my car is turbo tho and no OMP i premix only

ebodyboy

Walmart has many 'brands' of oil - - including Castrol, Pennzoil and Valvoline, plus a variety of synthetics. Obviously they do not bottle it themselves.
Knew a guy couple decades ago with a big Harley. He only used the (dealer-offered) H.D. motor oil. I tried to tell him to go by the viscosity and specifications that (Harley) recommends - - and he still wouldn't listen. Such is life.

chuyler1

iTrader: (1)

Walmart sets the prices, vendors adjust their product to maintain profits. If you've ever bought a bag of m&ms from Walmart and compared the number of odd lumpy ones in the bag compared to any other retail store, you'll understand what I'm saying. Sure, Castrol may bottle the oil, but it wouldn't surprise me if the formula is slightly different or it hasn't been though the same quality testing.

With that said... 10w30 in winter (I don't drive it much unless the roads are dry) and 20w50 for the summer when I do track days. Non synthetic unless you've blocked off the OMP.

Maxwedge

iTrader: (1)

Totally agree. Synthetics are designed to not burn or break down from heat. Great for lubing bearings but not as great for lubing fuel. Our fuel should be able to lube the seals and chamber but still burn away with the gas, not leaving any baked-on coating behind (carbon). I've heard/read people pointing out that the factory teams used synthetic. Probably, but they tore down the motors after every race, so it's not at all comparable to long-term street use. I use synthetic (Mobil1) in my turbo Subie but good ol' Castrol GTX in my FB..

chuyler1

iTrader: (1)

Factory teams almost exclusively ran PP with premix, but even if I'm wrong about that, you're still right about lifespan of their engines.

Maxwedge

iTrader: (1)

They put PeePee in their fuel tanks? What? Yucky!

jburroughs12

Has anyone looked into a synthetic blend/high zinc content specialty oil like Brad Penn? I know we use that in air cooled Porsches because of the zinc content, but not sure if a specialty oil like that would have any benefit/detraction for the rotary.

t_g_farrell

iTrader: (1)

PP == Peripheral Port, not peepee.

Supposedly the synthetics now all burn up like dino does but who knows for sure. Stick with Castrol.

ebodyboy

Brad Penn? - - He was great in Devil's Own - with Harrison Ford. () Now, as far as Walmart or other big, versatile retailers, they purchase their stocks of oil and additives from whatever supply source (middle-man). How much profit would, for example, Costco achieve selling oil, filters and additives by the case? Not a lot if they set low prices. These big wholesalers and retailers make a little profit on almost everything. Frequently they offer significant price cuts to advertise in weekly flyers - - to bring in the customers (and misc. shop-a-holics). It all ads up. No way would any company like Castrol, etc. have same labelling on top-line and inferior products. The specs. are listed on each label and the law says the product must meet these claims. Cheaper or inferior products would have different labelling. Canadian Tire for sure offers a variety of oils with a variety of additives and they are packaged and priced to offer choices to the consumers.
Lucas has a very good 'high zinc' motor oil labelled as Hot Rod and Classic. There is NO API spec rating on container. They do, however, put on the label that the product is 'Not recommended for passenger cars with catalytic converters requiring (API) service oils." All the other anti-wear claims are on the label. The only one I've used is their 10W-30 grade for break-in. And, No, not in a rotary (with cat-cons).
Just about from 'day-one' I began using (thinner) additives, with my usual 10W-40, with good results. Best one to date has been Duralube. Like many others, it's in a 10W-30 base so will flow well through the auxiliary tubes that lube apex seals (under stress). Usual 20W-50 a bit too 'heavy' for my liking. If I was in very hot climes, such as Arizona, I would maybe consider a 10W-50, but ultimately I prefer to combat heat and friction with a good additive. So far, so good. Oh, and changing the filter more often than the oil itself also on my maintenance list.
Remember, it's primarily about general lubrication and not to mainly take up the excess clearance in bearings and rings (of piston engines). Look at the suggested oil specs for new turbo and supercharged engines. Most seem to be 5W-20, so why would a rotary command 20W-50?
It's always good to hear various preferences and results (based on personal use). If someone says to me "my neighbor uses such and such viscosity and brand - - so maybe I'll use it too", that is also something to investigate and consider.

chuyler1

iTrader: (1)

I had much better hot starts after sessions at the track when I switched from 10W-30 to 20W-50...but if I left that in over winter it would result in hard cold starts.

You can choose to believe what you want regarding Walmart but they buy their stock in huge bulk, and they will refuse to put a vendor's product on their shelf if they don't agree to their price. Some vendors just take the loss, others adjust their product to maintain their profits. With electronics, especially around the holidays, you'll see different model numbers on what appear to be the same TV sold elsewhere costing more. Those TVs are often built to lower tolerances and will still work, but they may not last quite as long, but they meet the price Walmart wants to advertise while allowing the vendor to still make some profit. I'm not saying Castrol and other oil vendors do this, I honestly have no idea, but if the prices is significantly cheaper, guaranteed there is a reason.

j9fd3s

iTrader: (3)

the rotary is nice because it doesn't care so much about the oil you put in it, as long as there is some, and its fresh.

no cams, no timing chains, no VVT things...

rx7junkie170

Yea guys so imma just run castrol gtx 10w40 from now on with k&n oil filters thanks

TimNH

Late to the conversation, but for what it is worth. I have only used Castrol 20W-50 in my rotaries. I've had my RX-7 for 23 years. I bought it with about 120K and it now has close to 190K. Still on the original engine. I now get my oil at Walmart in 5 Qt. jugs. I'm paying around $18. They were out of Castrol last fall so I had to go to AutoZone. They wanted $30. Oh well, nothing but the best for the old girl. I don't run it in the winter, don't like to even start if it is under 40 0F. The oil is always too clear to see on the dip stick just before I change it at 3K miles.

Once, way back in the day, we took a cross country trip in our RX-4 wagon. That engine used oil so I had to top it off any day we did 700 miles +. We were out west when the store we stopped at didn't carry Castrol and only had Kendall 20W-50 racing oil. We had to add oil the next day at the lunch stop and 350 miles. Back to Castrol and back to 700+ miles per quart.

I use a variety of oil in our other cars, but it is only Castrol 20W-50 in the RX-7.

GSLSEforme

Same here with either Wix or K&N filters. K&N preferred.

TimNH

I have used Fram filters. Buy them at Rock Auto these days for $2. They seem to work.

GSLSEforme

There’s a reason you’re getting them for $2- they’re crap. The Fram brand is nothing more than a name at this point. The company has been bought and sold so many times what they produce under the Fram name has absolutely nothing to do with the product put out 20 years ago. The present owners are trading on name recognition. They are the bottom of the barrel in quality,filtering capacity and construction.

If if you care about your engine as far as oil and filters go,spend a little more and give it something better.

chuyler1

iTrader: (1)

I'd use a K&N filter for 10k miles before I risked a Fram for 3k.

TimNH

190K miles on the engine. Must be junk. Can't see the oil on the dip stick at 3K mile oil change. Must be letting all the dirt by. Are there better filters? I'm sure there are, but I guess since I've never seen a problem with a Fram filter in over 45 years of use on maybe 20 different cars and trucks, I'll give them a break. Could you have fallen for all the marketing hype?

t_g_farrell

iTrader: (1)

Ah, the beginning of an endless thread. I love it!

Maxwedge

iTrader: (1)

Here is an independent study someone did on the construction of the popular filter brands. He dissected 20 or so oil filters and describes the filter media, anti-drainback valves, wall thickness, etc etc.. It is from 2003(?) and doesn't list the K&N.

https://www.austincc.edu/wkibbe/oilfilterstudy.htm

Most of the Frams, as Everyone knows, are garbage (standard "Extra Guard" and "Double Guard" models), although he said the middle-of-the-road "Tough Guard" is better in most ways than it's lesser brothers. But it still uses cardboard where other brands use metal, so on a performance engine, especially a rare collector car (RX-7), why not spend $5 instead of $2?

I used Fram Extra Guard oil filters in the 80's and early 90's and never had a problem. Then I got on the K&N bandwagon and used them for a while. During that time I read an article in one of the V8 magazines (Super Chevy or Chevy High Performance) about the Fram name being sold to some Asian conglomerate and the quality disappearing overnight. I've used Mobil1 filters (or OE) on all my vehicles since.