High Octane In Latest Gen. Hybrids?

[HDPete]

Hi all,

as per my post in the new member's forum, I'm in the process of getting a '13 GS450h.

I've previously run a Porsche Cayenne on Super Unleaded and more recently LPG. The difference between standard 95 and 98-99 octane was huge with this engine. With LPG (105) it was even better.

I know that this can be a contentious issue, but are there any owner experiences with the 450h engines and whether they offer any improved MPG or performance when run on higher octane fuels?

Regards

Peter

[ColinBarber]

Hi Peter, no direct experience with that particular engine but on other Toyota/Lexus engines, including a hybrid, I've seen a small increase in mpg. Super unleaded is quite expensive where I am so the cost per mile ended up being slightly worse so I've never continued to use it.

[noby76]

Just look in the owners manual when you pick the car up Peter and it will state the minimum octane fuel to run in the car. e.g My previous V6 ford cougar 's manual stated the engine was designed and mapped to 95RON fuels so using anything higher than that wont benefit the engine. Lexus states
"95RON or more" for the IS300 so i alternate between the Shell normal and Shell V power fuels and noticed there was not much of a difference between the two fuel formulations in normal driving but where the V power comes alive is when the engine is nice and hot and operated within higher revs. I have noticed the engine is still happy to rev quickly when it hits 5000rpm to redline when in higher gears compared to when running 95RON. I have switched to shell normal unleaded after running its high octane for over 6 months continioulsy and am now seeing the difference in the engines behavior when operating it in the higher rpms. am noticing a slight slugishness at higher rpms on normal unleaded which makes me think if one will be subjecting thier cars to higher rpms most of the time then they might benefit from high octane but for day to day driving i did not notice any difference in lower rpms only diference was at higher rpms where the engine feels a bit strangled and unwilling to rev faster to redline although it does get there, it does it in a sluggish manner compared to v power. main reason for me running high octane is they include higher concentrations of engine, valves and exhaust cleaning aditives which cleanes the engines systems as one drives and a clean engine will always perform better.

only way to find out if 450H does benefit is to run normal unleaded for a while stick it on a dyno to see the power and tourque curves then dyno the car again after running high octane for a while and compare the results.