You'd be hard pressed to come up with a summary in light of all the differing opinions/results here. 1/2 ounce per gallon of gas (1:256) seems to be a popular ratio, but don't forget to factor in the oil injected by the OMP. Too much of the stuff might clog your fuel filter, but it seems that the fuel filter clogging some experienced was caused more so by low quality gas, cold temperatures, using 2-cycle oil not designed for premixing, or combining it with other fuel additives (esp. Lucas UCL). Avoid these factors if you can.

Your best bet would be to premix with a proven synthetic product: Idemitsu, Amsoil Saber, Royal Purple. Lube Control FP60/Plus seems to be both compatible with premix and an effective fuel system cleaner/lubricant. But it's no substitute for premix oil. Add your cocktail of choice to the tank just before you fill up to ensure complete mixing. Lather, rinse, repeat.

 

^ Thanks.. Does it matter what octane of gas you run? I've been running 87 without problems for the longest time. I'm guessing I should bump up to 89/91 if I premix? (I use Shell or Chevron which seems to be the best.)

 

Should be OK.

Two stroke oil can seriously depress the octane rating, but with the ratios we are using, being well over 150:1, the net effect should be negligible......

S

 

I believe OD said, in another thread, that he was running Idemitsu premix with UCL. He pulled the pump and it was fouled. Stealth is running synth 2-stroke with UCL and hasn't had any issues (right?)

Also, I ordered a case of Idemitsu premix from Mazdatrix and they are out of stock (as expected). Chris, the rep I spoke with, says they will have stock 1st week in October. My plan was to premix Idemitsu with UCL but in light of the pump problems I may just stick with the Idemitsu. I ran my first tank of just UCL (4 oz) this week. My car runs smooth as is, since it's new and broken-in, but the UCL did seem to help. Could be the placebo effect though.

 

I believe that Idemitsu is supposed to have cleaning additives as well as lubricating so mixing it with UCL may in fact be pointless .

 

Thats what I was thinking, based on what Idemitsu claims, but at least a few members of the forum mix the two. I was wondering the same thing myself.

 

Idemitsu Rotary Premix (IRP) does have some cleaners, but is a designed lubricant, with a few cleaning ingredients to keep from gumming things up too much - it should not really be thought of as a "cleaner" per se. See Linky below for ingredients:

http://www.patentstorm.us/patents/5308524-fulltext.html

Adding some FP60 or FP plus will assure the rich fuel mixture with the Premix/OMP oil addition will not carbon things up as much as these are excellent cleaners that happens to be very lubricious as well - they will not impact the oil lubricating film like many cleaners will.

3 oz of IRP with 2 oz of FP Plus (or 3 oz of FP60) per 12 gallon refill is what I use and recommend. You could go with 4oz IRP and 1 oz of FP Plus (2 oz of FP60) if you want to err on the lubrication side a little.

Lucas UCL is a good lubricant, but not really a very good cleaner, so it is kind of redundant to mix this with any 2-cycle as it's formula is much like a 2-cycle. Also, several here that have had the fuel pump clogging issues have been using LUCL with other products - don't know for sure if it's a factor or not - but I if I wanted to use LUCL I would use it alone and would not mix with other additives.

 

1. Cold weather does affect miscibility of any premix, IRP included. IRP is more miscible than most and is tested to -25C as it uses short chain hydrocarbon oils (5-14 carbon atoms) that mix especially well (longer chain oils that are used by some 2-cycles are not as miscible).

If you need more miscibility in the dead of winter, mixing it with a thinner cleaner/lubricant, like FP Plus, MMO, etc., that has some solvents in it does help the miscibility.

2. Short chain 2-cycles, IRP included, will not "settle out" of the fuel once it has been thoroughly mixed in from the fill up (2-cycles with long chain oils can and sometime do as things get colder). So, you should not have any starting issues if your car sits a while with IRP premix. Mine has sat for several weeks without being driven and I have never had an issue.

 

2-stroke oil can get quite thick in the bottle at minus 20* or lower (!), but once mixed there should be no problems - it's used in snowmobiles.

S

 

On that issue, read this from Royal Purple's site:

here: http://www.royalpurple.com/prodsi/tcwiiii.html

How many RX-8 owners really live in climates with temperatures below 20 deg F, though?

 

A LOT of them. There are quite a few owners in Canada and colder US climates. I live near Washington DC, it routinely dips below 20 degrees here in the winter.

 

....this will be it's fifth winter as a daily driver.

S

 

mixing lucus top cylinder and premix is not a thing to do. I learned the hard way. So yall are right on.
olddragger

 

DAM! Mine always is in the 90+ range.

 

I hate you......

S

 

DITTO.

And is your avatar a photo of where you park your car?

 

Being that the IRP is out of stock, I am thinking of starting with the Amsoil Saber.
I'm thinking of getting the 3.5oz bottles and using that are fillups. (10-gallonish).
As far as a cleaner, would 2 oz of FP 60 work?

Thanks

 

Make sure to use the Amsoil Saber Professional as it is full synthetic, not normal Saber which is a dino 2-cycle.

Those "3.5 oz" bottles you are referring to usually hold about 5 oz if you fill them all the way up - so you should have room for your 3 oz of 2-cycle plus 2oz of FP60 (good amount).

 

After doing the math, it made more sense to get the quart bottles. So I'll prob do the dixie cup method. Thanks for the help, it's awesome having knowledgeable guys like you on here.

 

One nice way to measure and dump in the mix is to buy a 32oz bottle of "Sta-bil" fuel stabilizer ($12) and just dump it out and use the bottle since it has built in dosing, a long neck and refillable. Also large enough to get 8 fill ups out of it before needing to refill.

 

Does not sound like you guys have been following the thread where we have been discussing increased premixing and its effect on fuel economy .
I am doing a trial myself to see if I get similar results to what others have been finding . AT 180:1 ratio I got 500kms from my last tank (110-120 km/hr cruising mostly and 55litres used) which is an alltime record for me . Previous best was around 440km so thats better than 10% improvement . Inconclusive for me at this stage as that was only one tank - but looking good .

 

I'll know this weekend how mine has improved. Mixing 4-5 ounces per tank of UCL. What ratio's is anyone else using with UCL? Just curious.

Started premixing with UCL a few weeks ago. I also changed plugs and air filter all at the same time. I can tell a big difference in the way the car runs now. I figured its probably a combination of all those things put together.

 

I just put in 4oz of UCL with my last fill-up. Too early to report results as I decided not to measure fuel economy this time, but the engine does seem to be idle smoother. Could be my imagination.

I ordered a case of Idemitsu Rotary Premix from Mazdatrix. They are on backorder until next week supposedly. I'm going to finish my bottle of UCL then switch over when the Idem comes in.

 

I noticed with mixed driving I was getting ~19.5 mpg when I was mixing the UCL at 4oz a fillup but I have since run out of it and also plan to switch to FP60 and Idemitsu so I'm flushing the tank with 3-4 full tanks with no UCL just to be safe. But now without the premix I'm averaging 18 mpg... Nothing too scientific but my mileage is definatly down.

 

180:1? that's 11 oz's per tank? (MOP on or off?)