I've been using 30, but getting a new engine tomorrow. I want to break it in with 20% because I think it will be getting better lubricated, and the performance will be relativley the same.

Someone correct me if I am wrong. Is 20% just a better all the way around better way to go?

i would say yes. i used 10% in mine cause i like to keep my engines for a pretty long time and im not to anal about speed most the time

hey markhat i see you live in AZ so come join us at
http://www.az-rcfreaks.com/freaks/index.php
unless you have already

I'll head over to that site. Cool. I pretty much race at SRS. I'll start hitting Papago's new track layout if he gets it put back together, and maybe the Pit, but mostly SRS.

I'm hoping to hear a lot of thoughts on this nitro thread. I am due for fuel and want a change from the Sidewinder 30 I've been using.

well all i can say is join the site i gave my input already

The only thing that 30% fuel wears out faster is your connecting rod and bearings. Your piston and sleeve is still getting the same exact lubrication regardless of the nitro % (as long as the fuel your using has good quality lubricants) so the piston and sleeve will last just as long on 30% as it will on 20%. There might be a slight difference probably due to the engine reaching higher RPMs but thats about it.

Theres still nothing wrong with 20% nitro. With off-road its more about driver and setup than it is about power.

30% heats up more also

You said it.....driver set up. I'm convinced I won't go any faster cuz of the fuel, so why not have better lubricant?? This is the point I am trying to make, just looking for someone to give a good argument in favor of 30%.

well it would go a bit faster

and run cooler not hotter

guys honestly if your running 30% youll be better off, i had three RTR engines on 20% and now im on my second race engine on 30%. It runs cooler (yes i mean cooler) easier to tune, and they last just as long if not longer than my 20% engines. honestly ppl freak out about 30% but its not that much of a big deal, just use the 30% and enjoy the benifits.

Markhat250 it has been proven that 30% fuel is wayyyyy higher in performance than 20%. They dynoed it in RC Driver, and they said it has the same lubrication content as 20% fuel.... just food for thought man.

I like 25%. Most of the Italian motors are designed for 25%. Byrons race 25% has been working well for me for a long time.

yeah I think 25% is the best compromise in turns of performance and engine life.

hmm i guess i was wrong but im pretty sure i read lot that 30% gets hotter

My engines have all run cooler on 30% and there is an increse in proformance

my engines run cooler with 30% also actually its 33%

i promise you that there is no drop in engine life, just gains in performance. the only engine life drop you could see is that it might bite the dirt a 1/4th of a gallon sooner.

nitro has nothing to do with engine life, its the oil type and oil percent that effects engine life..

grow some and get the 30%.

most ppl run 20% because of EFRA...

I'm actually thinking of trying that O'Donnels 60% Race Blend. Of coarse id shimm my engine accordenly.

i beleive that's for boats..

30% fuel will ignite sooner so if your head isn't shimmed correctly (with some engines you need to take away some compression) you can get pre-ignition. If you have pre-ignition then your engine will be nearly impossible to tune and run hotter along with blowing out glow plugs. Most .21 engines are shimmed for 25%-30% nitro.

They still use the same lubricants in the 30% nitro fuels if not they use better lubricants which can help your engine last longer. Also keep in mind just because something has only 8% oil content like Odonnel's 30% race blend that doesn't mean your engine wont last as long. Its more about the quality of the lubricants then the amount. In fact more lubricant % can make some engines run worse especially the on-road .21s.

sorry i ment 50% race blend

http://www2.towerhobbies.com/cgi-bin...&I=LXMGF0&P=SM

that stuff would have to reduce engine life surely?

25% here and never had a problem. I've prematurely broke one con rod in 6 years.
Higher % nitro burns cooler as the combustion temperature of nitro is less than methanol, therefore the more nitro the cooler your engine runs.
You can use 30% and shim you engine, with little loss of longevity, however if you don't re-shim you engine it can kill it quicker. (check you individual engine instructions)
I use 25% cos I believe that shimming an engine reduces the power in order to get more power from the fuel, which seems a bit pointless to me. Plus nitro is more expensive and I can run lower % fuel if I can't get hold of my usual stuff without removing shims.
20% will be fine though. Most engines out of the box will run well on 16%-25% with no adjustments.

25% all the way,best of both worlds!there is a happy med for every thing in life

not always....on hot humid days 30 percent runs cooler.....