Do I need to run premium in my 07 250XS optimax or not?

[Tamale]

It is not the ProXS and I have read conflicting reports. Do I need to run premium in the OPtimax 250XS? I dont have an owners manual.

[EuropeanAM]

When requesting engine-specific information, it's ALWAYS best to provide your engine's SPECIFIC SERIAL NUMBER.

A 2006 and up 250XS engines utilize 87 octane fuel (minimum octane). I actually recommend nothing higher than 89 in these engines.

Further information is always available in the "Commonly Asked- Commonly Used" sticky post a the top of this forum.

[jclark408]

I may be incorrect but running high octane (93) can actually cause problems over time as it leaves more residual carbon buildup in the post-combustion areas of the engine

100% sure you need to use 87 octane and the additives you see fit................as for me (250 XS, 2008), I have Ethanol free gas so all I use is Quickleen and I rarely ever see any buildup in my prop hub at all

[Tamale]

Thanks for the comments fellas.

Here is the Serial Number: 1E001699
It suppose to be a 2007 Model but says this on it "2006 250XS L"

[EuropeanAM]

87 Octane fuel minimum.

I'd run no higher than 89 octane.

Higher octane fuels burn SLOWER and COOLER- resulting in less power output, and an incomplete burn (which results in carbon buildup).

[hempbake1]

What fuel should I run in a 2008 250 proxs? I have been running 91.

[Reelsore]

Only run 87 octane in that 08. 89 is OK but it is recommended that you only run 87 in it. There has been alot of discussion on this topic on the BBC. If you look at the stickies at the top of the page, there is a ton of very helpful information up there regarding these motors. Oh by the way, welcome to the BBC.

[NAVISPEED1]

Is there's any noticeable difference in performance between the two 250xs models?
(92 vs 87octane) just curious, I've heard that the 92 octane is hotter than the newer 87 octane one!!

[EuropeanAM]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by NAVISPEED1 &raquo;</td></tr><tr><td class="quote">Is there's any noticeable difference in performance between the two 250xs models?
(92 vs 87octane) just curious, I've heard that the 92 octane is hotter than the newer 87 octane one!! </td></tr></table>

On the 250 Optimax models, the 250XS (2003-2005) required HIGH TEST (91 or higher) octane fuel. These engines had a slight edge on their later counterparts... averaging about 274hp at the propshaft (about 6hp stronger).

[tcd8383]

I have an 05 250xs optimax with a fully dress 2008 powerhead, what octane should i be running?

[EuropeanAM]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by tcd8383 &raquo;</td></tr><tr><td class="quote">I have an 05 250xs optimax with a fully dress 2008 powerhead, what octane should i be running?</td></tr></table>

If you're still running the '05 250XS electronics.... it's still an '05 (and should run HIGH TEST or 91+ octane fuel).