DrRock

I really wish we could do away with ethanol. It has become a sacred cow for those involved with it but it causes issues with vehicles, takes a lot of water, land, fertilizer/pesticides, and energy to process. I have had two Ducati motorcycles that needed multiple tanks replaced because they have plastic fuel tanks and the ethanol causes absorption and swelling of the tank. The Italian designers didn't take ethanol into account when designing the tanks. Sorry for the quick rant.

ballistice

It's the bike not the fuel. Sorry you had to find that out the hard way. Ethanol does not do any more damage to tanks than straight gas. Multiple bikes here with plastic tanks and still going strong. Plastic tanks swell naturally when temps and elevations increase.

ASE

Ethanol absorbing water and breaking down causes a range of problems. Best to use non-ethanol fuel ... or keep refreshed by consuming inside of 60-days.

DrRock

Actually no it is the fuel but thank you. Ducati’s tank maker changed to a different type of plastic Around 2010, but from 05-10 ethanol sitting in the tanks would cause swelling and blistering. If you google this you will find much more info but here is one.

• If the Ducati has a plastic tank and you are in North America: Check for swelling in the tank, like bumps and blisters, or the tank bulging asymmetrically. If the latch is hard to open, or if the tank is too close to the ignition shroud, it’s a sign of swelling. Swelling in the plastic tanks was caused by ethanol mixed into North American gasoline. It was a known problem, and for a while, Ducati was offering replacements. If your tank has no swelling, it may have been replaced (which is good). Of course, if the owner has evidence of this, all the better.

John00

the octane rating on the pump isnt what it has to be, its the minimum it has to be. a majority of the time you will get a higher octane than the label if you use the lowest value. this is because more often than not it is cheaper to just make the mid and high grade instead of 3 separate process lines.

userlexusgx

Can I mix my 2015 lexus gx460 with 87 and 93 octane to make 90 octance?

bootman

https://www.cars.com/articles/mix-re...e-pump-448191/

catdaddylo

I have been doing this for all of my vehicles that require 90 octane. I keep the recite when I fill up my tank and write the octane on it and place it in one of the cup holders. When my tank is half empty (full) I fill up with the octane that will keep my tank at 91. I do this for my in town driving. On road trips I use the high octane every fill up because I don't stop for gas until my tank is almost empty.

John00

LOL seems like more time than benefit., >180,000 miles, I always use the lowest. never ever noticed any knock. seems the ECUs keep it under control.

ASE

Never understood the controversy on this subject ... knock sensors in modern vehicles will retard the ignition to prevent detonation so as to prevent engine damage. Gasoline has an energy value ... no matter the octane ... all exactly the same ... but with higher octane, the engine can advance the timing for maximum power under high(er) load conditions ... so yes, higher octane does provide increased engine output under these circumstances ... but for anything less than towing or under heavy load like climbing hills or under heavy acceleration and such ... the 89 mid-grade (87-89-93) is just fine for commuting.

NewB2Lexus

I also never understood someone spending $60-70k on a luxury vehicle then trying to save $10 when paying $100 to fill up at the pump. Assuming you get 400 miles out of a full tank that is a whopping $2500 saving over the course of a 100k miles or a whopping $5000 saving over the expected useful lifetime (200k miles) of the vehicle.
But of course it is a personal choice, while I did fill up the GX with regular a few times (station was out of premium) most of the time I use what's recommended by the manufacturer.

John00

I cant believe someone in this day and age would spend 70k on a used 2010, then think that higher octane actually helps in any way. It actually accelerates fatigue failure in certain polymers in the fuel train.

NewB2Lexus

I only believe this when you post some educated proof of it and that the GX, which was designed to use premium fuel, will suffer negative consequences of using such.

ASE

89 for commuting ... 91-93 for heavy loading ... towing or accelerating over mountain passes. Simple. 87 octane is for Lawn Mowers ... or for those that simply do not care ... the knock sensor will adapt accordingly. Just make sure to use "Top-Tier" gasoline no matter the octane.

ASE

The Knock Sensor retards the ignition to prevent engine damage ... with the associated reduction in power output. All good if maximum engine power is not required.

We're not talking about a pre-knock-sensor vehicle here ... where the ignition timing is a fixed profile based on RPM's ... where octane is a major consideration when dealing with high(er) compression ratios.