jizz4jazz

iTrader: (1)

I've been using 87 on my Is250 for years, it still runs and drives like new.

DennisMik

I've has my 10 IS250 since 2014 and have never used anything other that 89 octane. Runs like a champ.

Shadowfire

I bought my 06 is350 last feb always been running 91oct because it was the highest I could find my car run great on it , about 2 weeks about I went into chevron, and they have 94oct, so I used that, and I am not sure if it's just in my head or not, but my car seems to actually run even smoother plus I seem to have a little buit better gas mileage, I only drive to work 4 days a week 25 Km each way I may put this higher octane in and pay closer attention to it , the only reason I put it in because of the apparent additives that supposedly help with fuel injectors

2013FSport

iTrader: (2)

In previous cars, running 89 octane always paid for itself compared to 87 as the vehicle range increased paying the extra 10cents a gallon ($1.50).

The 350 requires 91 or better and when mixed with 97, she really comes alive. Anyone that knows high compression engines, knows they'll perform better with higher grade fuel.

To each their own. You do your thing, I'll do mine.

Shadowfire

if I could find that high of octane few I would run it but the highest I can find is 94 without buying a can of additives. Back in the day when we used to build what we called mustang killers Dodge big blocks and wide block strokers we used to use octane boosters just to the cars would idle a little more smoothly, they never really gained much though just a little off the line.

2013FSport

iTrader: (2)

If these detect detonation, the first order of business is pulling back the timing and to a lesser extent adding fuel if the calculated load must be maintained. So, unlike our old school days of statically fixed ignition limits, these can we they detect zero detonation and will advance the timing within limits of course.

Ya, I come from the relam of 5.7 and 7.8 liter engines where displacement gets the job done. The difference being those engine weren't pushing 12.0:1 C/R ratio

Bdiamond70

Can anyone please letme know if its ok to run 87 octane fuel in my 2008 IS250?
I realize the owners manual says to only run premium fuel but i was juat wondering if it is really required and if im going to do any damage to my engine if i do run 87?

MikeyStyle

i'd follow the manual for longevity

AmyUD06

iTrader: (1)

Seriously. If $16 more a fill up is going to break the bank, you probably shouldn't be owning a luxury car, even an older one like this.

firestart9

The normal answer is NO. Regular or mid-grade won't harm your car and you can drive it normally. The ECU should adjust.

The difference here is NOT because the IS250 is "luxury" but because its direct-injection, most people swear by 91 to prevent carbon build up.

I have no idea if that's true or not tho! I was just told to change the oil at 4,000 km to avoid carbon build-up.

mikessolis

I disagree. This forum is for older cars. How do we know he didn't pay 6 or 7k for this vehicle.

Zmon

iTrader: (2)

The 250 engine was designed in an era where they weren't sure how direct injection alone would impact things, but kind of funny that they had an epiphany about the 350 and did port and direct injection (350 has no known carbon build up issues since the port injectors clean the valves). Obviously this has changed within the last 5 years since Toyota now has a self cleaning function on their direct injected engines now.

It is still a luxury car that requires premium gas, age simply doesn't matter. It's what the engineers who designed the engine said it needs and it's clearly stated in the manual. Many older luxury cars end up going into the shop for sensor issues because of other people thinking like this. Unless anyone here specifically works for Toyota in their engineering department, it's probably safe to say nobody here is qualified to make a statement on gas requirements besides what is stated in your manual.

If you want to use it as a beater and simply don't care, by all means it's your car so run whatever you want. Don't be surprised if that mechanic bill comes in sooner though.

2013FSport

iTrader: (2)

^^ That was brilliant!

This is just my observation among several manufacturers, running crap gas where the requirements calls out otherwise, the engine is tested by means of stray bullets if you will. i.e. in order for the ecu to determine optimal fuel and ignition advance it must test the waters. In doing so it induces detonation. Detonation erodes everything in the combustion chamber and induces significant shock to the piston, rings, rod and bearings as well as the crank.

Now add in the dual knock sensors that can randomly fail of their own will and basically abuse them and well, they fail even sooner.

Let's just say cheap fuel is not a suggested practice for this vehicle or anything else having higher requirements and/or compression ratios!

As for lesser grades crating more build up, it depends who you buy from. That said, makers like Shell and 76 and to a lesser extent Chevron, add different packages to their three blends. The more you pay the better the cleaning package is. Feel free to correct me on this last bit. Just going off from their advertising.