Yamaha TRX850 Enthusiasts Forum

Anybody done any tests on using super unleaded in the bike instead of the standard stuff? 99 to 95, and if you were using it over time would there be more or less wear on the engine from the difference in detonation?? Just a thought whilst I was filling up the wifes car this afternoon. I'm sure the teccies amongst you must have some answers!

Dave E

super is normally 97 but I've noticed a fair amount of 99 around

not worth spending the money on IMO (although I always use the highest octrance I can o the track for some reason)

Tesco is doing super and states 99! It was just a thought as to whether it would actually shorten the life of the engine, more top end rebuilds?

Dave E

slow codger wrote: Tesco is doing super and states 99! It was just a thought as to whether it would actually shorten the life of the engine, more top end rebuilds?

Dave E

there is an argument that says higher octance fuels produce more efficient burn and greater compression but the difference is only minimal so I wouldn't worry (or waste my money)

Yep agreed, unless the motors `aggressively `tuned and running much higher compression the difference is really not going to be felt, nor would any improvements or decreases in wear be expected either.

I've tried it a few times and noticed a slight improvement in performance .... probably due to my wallet being that much lighter !!!

The only real benefit you would get from using the 'super' grade fuels is that they have additives added that help clean jets etc - more for fuel injection systems but should do the same to jets (Unless, as stated, you have a tuned motor). Some of the fuel stations by race tracks have 107 RON rated fuel - its the stuff you can buy in tins labled as race fuel. Only problem is it that at about £1.70/lt not many bother buying it so it stays in the tank a while, and as fuel 'goes off' after 6 weeks the fuel is probobly no better, if not worse, than regular UL. Bit of a wander off topic there but it's all relevant!

In MotorCycle News of 24 August, Kevin Ash write that super-unleaded is most beneficial if your bike has a knock sensor, in which case a power increase of up to 10% may be experienced because the ECU will give the maximum possible ignition advance without "pinking" (as "knocking" used to be called!).

(Does the TRX have a "knock sensor"?)

However, I happened to chat to the chap who run K2 Bikes in Stoke, who says super-unleaded yielded good results with his TDM. So I filled my tank with the stuff, and it really did seem to make the engine pick up more smoothly. Of course, it may be a placebo effect, but my 18,500 mile TRX is running better now than ever before.

Super unleaded smells nice

only recently here on aussie tv, a test was conducted with 4 identical cars( albeit one being diesel).
all 4 had the fuel run dry,carried identical weight(drivers balanced with bags of flour to equal out) then had 3 litres of each fuel E10, 95, 98 and diesel put in.
the diesel was most effective for economy with the 98 being the most cost effective of the petrols; next E10 then 95.
i run all my vehicles on 98 with good result.
mind you the only one to have a stripdown was my old '78 323 wagon and it was in surprisingly good nick for a 200,000 plus 4 cylinder.
cheers
fung

I did a dyno test on my Duke with hi oct pump fuel,then drained it and tried some ELF race fuel(101)... the ELF cost me $130 for 20 litres and the dyno measured a 1hp gain, however the Dyno guy said that could just be a dyno variable, so really no difference in my case, except the ELF smelt really good. So in summing up, if you are a "strong after shave" type of guy, buy ELF.

the option on the higher octane issue seems to come down to personal application..being in the motor trade here in OZ and the kilometers that i have seen leaves my thoughts that the cleaner you can run the motor/chain/transmission..ect..the better it will give in return..i have stripped down car motors that have 500,000 kays and the big end journals have just lost their sheen..regular servicing..with the fuel, i only use the 98 ron BP as it is the best performer coupled with an upper valve fluid...everything..my 2.5 subaru, mazda 2 , and Sooty [ the trx]..keep it clean and you can treat it mean..[there are many advantages of that]..heh heh..i have used the 95 ron in the trx and it seems ok.....so ok, heres my stand..keep it synth/mineral based..oil...95-98 ron for the fuel..a lick of fuel additive for the bouncing bits.[face it , they are under as much stress as my missus]...and get stuck in...heh heh

Funny that about BP fuel...I've always tried to run the bike on it also as found a better response ustilising it also and no different in running fuel additive to keep it clean

+ 1 for BP ultimate.
Cannot stand Shell except for their avgas. i used to get it for $1 a litre from the old tigermoth bloke at carrara when there used to be an airstrip in the centre (pre emerald lakes).
cheers
fung

I have done comparisons over the last year running both 95 and 99.On the bike I achieve about 240-250 km on 95 and 280-300 km on 99. This is based on conservative riding. The cost difference is about $3-$6 per tank. I believe it runs slightly smoother on 99 as i ran it on each fuel for three tanks to compare. We have three vehicles and I have compared fuel on all three. The most noticable is my wifes ford territory SUV 4 litre 6 cylinder which pings and rattles its head off on 95 and causes low revs at idle which makes the power steering rack shudder at idle speed. Then run two tanks of 99 through and it is back to smooth and refined and an extra 50km's per 99 tank = extra $7-$12 per tank. We decided to make the trade off and run 99 in all vehicles and to date our km travelled with no repairs = Ford 6 cylinder 209,000 km's Diahatsu 1.6l 248,000 km's and TRX 850 84,000'km's. Our oil changes are done earlier than manufacturers specs too. I have rebuilt and repaired many bikes and cars for myself over the years and have come to the conclusion that spending a little more on regular maintenance has saved me on major failures and rebuilds. I do track work on my TRX regularly and have had no major issues apart for some extra oil use as is renound for these bikes.

In Conclusion each to their own, does it change the fun factor on my TRX no bloody way!!!!

stay upright