The 13B MSP is an engineering marvel. Its two major problems are wear in the centre of the apex seal, due to lack of lubrication, and carbon build up. The former has probably been rectified by Mazda with a 3rd oil injection point over the centre of the apex seal. Carbon build up remains the biggest bugbear. If it becomes excessive, seals sieze and the engine needs a rebuild. People have suggested redlining the engine daily to prevent this , and though it sounds plausible, there are still many US RX8s that have needed engine rebuilds despite this.
E10 is basically ULP with ethanol. THis increases the octane rating to about 94.5 and can be run on our motors. Mazda confirms on its website that it is safe to run E10 on our engines. THe benefit of E10 for our engines is that the ethanol is excellent at removing carbon deposits, which may result in significant elongation of our engine life. An added benefit is that E10 is about 11c a litre cheaper to buy. The downside is that peak power may be slightly reduced. However this may not necessarily be the case. Taka used to run Shell V racing in his car, which had ethanol added to it , and his dyno figures suggested a significant increase in horsepower.
I have begun using E10 and have noted no change at all in the idling of the car, and cannot notice any difference in daily driving. Perhaps if I tracked the car I would notice a drop in laptime. Interestingly, I still get the same fuel economy from the car, even though I would have thought that it should have dropped about 3% as it has a lower energy output. Perhaps this is not the case with rotaries and E10.
I would be most interested to hear other peoples experiences and thoughts regarding this.

 

I have used e10 on occasions. much worse fuel economy (round town no highway). the cleaning may be there but my plugs had lots of carbon on them last change. I think you would have to use it regularly for the cleaning to be apparent.

 

There was a lengthy thread about this recently.
I have since been very particular about checking my fuel consumption.
Undoubtedly 98 octane without ethanol is the best by a long shot.
I recently got slightly better mileage out of the 98 than the 95 E10 but the road conditions were markedly different. The E10 economy was on freeways the 98RON was 250km of winding mountain roads.
However 95 E10 is better than 91 unleaded.
I find 91 octane fuel causes a lag around 4000 rpm. The 95 E10 doesn't.

Be aware that the majors sell 91 E10 which is absolute rubbish.

Mazda specifies 95RON E10 compatible.

It is interesting about the carbon argument.

 

We have a problem, being due to the fact our apex seals need to be lubricated, and the low level of lubricity of ethanol ...

The 98 Octane products from Shell, BP and Mobil are actually made to act as a lubricant as well, not quite as good as putting 100mL of 2-stroke in your tank every time you fill up, but it's better than the other fuels that are available.

 

Have been using E10 on my RX-8 for quite some time. The 94-ron is satisfactory for the 13B-MSP engine. A little range is lost but no biggy.

Funny you mention the carbon issue, a recent check of the plugs at the 14,000km mark shows excellent burn. I figured its due to me revving the engine every weekend after a weeks putting around by the wife.

Good info on the cleansing effects of the Ethanol. Will keep up the "Pre-mix" in the tank too.

REgards

 

I've been tempted to put pre-mix into the engine but I've always had a concern it would clog up the fuel filter, particularly if its left stagnant in the tank for a while...!

 

I have run penrite tententh for nearly 10,000k (since the turbo) at 150ml to a tank with no issues.

I ran the VPower racing on the track and found it to be fine. No noticable lack of power or gain, buit on the street I notice a significant loss of economy.

Cheers


Andrew

 

I've wanted to try that one out. Where did you get it from?

 

ProMaz, but I am pretty sure that autobarn stock it.

Cheers

Andrew

 

I should give it a burl when I finish my shell advance stuff off.

On a side note, I really like the smell of shell advance ... it smells like nitro.

 

Update on E10 running.
Disaster. After three tanks of E10 car began running rough , not idling smoothly Wanting to stall all the time and had no power . Pulled in to servo and topped up with Vortex 98 and car immediately began running normally. I will never use E10 again in the car and will go back to using 98. Costs more but never had a problem with it in 80000km.

 

Out of curiosity where did you buy the E10?
The car is specified for 95 RON.
If you used 91RON E10 I am not surprised.
Last week I bought 98RON non ethanol for $1.08.
At that price there is no reason to use E10.
Unfortunately it is now back over $1.20.

 

Umm, E10 is marketed as 91ron unleaded to smooth over the dummies for marketing reasons (may explain why you fell for it)

The simpliest research finds its actual rating is as listed in the opening post you have failed to read. Hence why its "Officially rated" as suitable for the RX-8.

Think of it this way, the RX-8 engine "Marketing name" is RENESIS. Its "real name" is a 13B-MSP. 90% of RX-8 owners are ignorant of the engines true name thus proving the effect marketing a product has & why people dont know or dont care about the 94RON rating for the E10

Must add that I am curious for the reason why SymSym's RX-8 ran like a dog on E10. Perhaps a bad batch...? Because if it was crap, I certainly would not be using it in mine..........

REgards

 

BP (and Caltex I believe) claim that their E10 is 91 octane. Shell claim 94 RON.
United, Neumann etc claim that their E10 is 95 RON.

I am not quite sure what I have fallen for.
I have been trying to document fuel consumption. It appears significantly weighted against the E10.
Unfortunately my wife has been driving the car lately and resetting the trip meter is too hard for her

 

Well, I've used the ethanol petrol a few times and noticed it caused cold starting problems and lack of acceleration after constant use from time to time. It also seemed to flatspot around 4000rpm with some fillups for some unknown reason ...

... I have a Manual RX8, I'd presume SymSym has the same ... DMRH has an Auto which only revs out to (correct me if I'm wrong) 7500rpm.

I would suggest ethanol only as a topup fuel if you like to drive enthusiastically due to the fact that the product is inconsistant. If you're doing long lazy country trips during the cooler months, I see no problem with using regular unleaded or ethanol blended petrol, however, during summer stick to 95+.

 

Dude, picked up the "Propaganda" brochure from Caltex when they started doing E10 in Sydney. Clearly states the Caltex version is rated at 94ron. Then a little time later found they where marketing it as the 91ron to make people relax & associate as normal ULP since 80% of all sales (Motor Magazine) are for the 91ron stuff. Personally use the Caltex stuff 100%.

Agreed though. It does reduce mileage but "Me no care" I get it for free.........

Unlikely the 4AT has anything to do with mine running well 100% all the time. Perhaps its due to the "RE-mapped" ECU from Knightsports as the IGN / fuel metering is altered from the OEM mapping.

REgards

 

It's not the transmission ... I was more hinting towards the fact that your engine only has 4 ports and is tuned differently.

Didn't someone's car stuff up after the knightsport's tune? I thought I heard someone had lost compression after they had it done.

 

You are right . It is now marketed as 91 RON. I think that they used to mix ULP with ethanol originally and this would make it 94 RON, and 10% ethanol adds about 3 RON. Methinks that they are now blending it with an 88RON mix to bring it up to 91 RON, hence the rough running in my car.

 

i have to ask. the furai it has 3 rotors and it runs on 100% ethanol

 

100% ethanol has an octane rating of over 100. Different to running 91 RON in our engines.

 

Where did you get your ethanol mix fuel from?

On a side-note after doing some of my own research (reading site information etc. etc.), E10 fuel is rated at a minimum of 91RON, however it can range up to 94.