Regular Unleaded or Premium Unleaded?
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Seems like there are opinions that support both sides of the coin here. But what about flip flopping fuels? Like this thread, I’m not sure what’s best for my truck yet (just got it). Any reason I should avoid switching back and forth between 87 and 91 or 93?
Wait, wait. Which side are you arguing? The quote above supports the decrease in boil temp with ethanol.
That because the vapor pressure drops off BELOW gas at that high an ethanol percentage. Vapor pressures act totally differently at E10 level.
Yes, more ethanol = lower boiling temp, depending on concentration, until the ethanol percentage goes above about E40. Then the line for the boil temp of E0 and ethanol gas cross on the graph. At E10 level, the boil temp is lower than E0 gasoline.
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ramangain
Clarksonian disciple
As they say, cite the graph unless it is your own math (data)
So, I'm waking this old thread up because of an interesting observation over the year. My 05 LC has 317k. At 287k, the fuel pump died and it was replaced and the fuel filter replaced. This was Feb '24. Starting around Oct '24, I would get these oddly intermittent long crank cycles. She'd start, but sometimes would sputter to life, other times fire right up. Anyway I assumed I got a faulty fuel pump but decided to run it until it died. April '25, after a camping trip, she completely stopped the long crank cycles and would fire right up as normal...and did this consistently all summer. This was running 87 octane, top tier fuels. My LC is my only vehicle, so I typically fill up every 5-6 days. Now, starting Oct '25..my occasional long crank cycles are back. Again, she always starts..but the starter spins longer, and then she will sputter to life. Here in Maryland, "Winter grade" fuel begins going in the ground in October. I did an experiment and ran two tanks of 89. ::Not one:: long crank cycles while 89 was in the tank. I switched back to 87 for a tank, and the occasional long crank cycles returned.
I've owned this cruiser for 11 years and have put 200k miles on it, and this is a new thing. Any ideas out there why she decides to want better fuel? Is there a sensor going bad or something? Something about "winter blend" fuel? I've looked around and can't find a definitive answer...and I know Mud members often know interesting bits of information.
I've owned this cruiser for 11 years and have put 200k miles on it, and this is a new thing. Any ideas out there why she decides to want better fuel? Is there a sensor going bad or something? Something about "winter blend" fuel? I've looked around and can't find a definitive answer...and I know Mud members often know interesting bits of information.
Lots more ethanol in the 89? You have some water ingress?
As I've said for years, the Land cruiser 100 was designed "to last 25 years at third world country". You aren't going to find premium gas in a third world country, and what you will find is probably not the best anyway..
That said, octane and ethanol plays zero, none, nil role in your long starting. It's pretty much an impossibility. If your fuel pump is good, your evaporative control system is in good shape, and your throttle body isn't gunked up, it doesn't matter what octane you use. Octane and ethanol content, within normal US standards, will not change a ong starting problem, even if it appears there's correlation. I would look at your fuel pump, or your evaporative control system, I think that's where your real problem lies.
I agree, logically it makes zero sense…but this is the data I’m collecting. I’m leaning toward “something” with the evap system…but the only code I get is the gas cap because my filler hole is out of round…I have a dongle that allows me to read and clear that code if it pops every couple months. I’ve cleaned sensors, changed filters, the fuel pump etc. again, it’s not the end of the world, and heck maybe it is a finicky fuel pump that only acts up from October - April for some reason. I’ve not gotten into relays or electrical things yet…I was going to last spring, but then the symptoms stopped completely. It’s not even super cold yet in MD, so I can’t really blame temp.
holloween
Anyone running 87 in an 07 LX470?
I barely drive my car so for the past 10 years I’ve only used 93. But Jesus it hurts dumping $100 into this thing every 200-250 miles. I don’t know how anyone is daily driving these things? You people have money growing on trees or what?
I barely drive my car so for the past 10 years I’ve only used 93. But Jesus it hurts dumping $100 into this thing every 200-250 miles. I don’t know how anyone is daily driving these things? You people have money growing on trees or what?
I have run 87 (only) in my '99 LX and '06 GX for many years with no issue. Modern engines (such as these are) will knock suffer pre-ignition (spark knock) on 87 (or 85, as we have here at higher elevation). Save the extra $1/gallon. You will lose a couple horsepower at full throttle.
For over 11 years I've run 87 in my '06 LC.
Costco 92 (10% ethanol) or 91 no ethanol in my 07 LX.
I can average over 19 mpg on a full highway tank with 91 no ethanol. The 92 with 10% will do about 17 in the same conditions.
I would love to see the timing maps for an 06/07 LC vs 06/07 LX to see if that “Premium Required” is actually being taken advantage of. They could have just as easily said “Premium Recommended” but they chose “Required” for a reason on the LX. Two very different labels.
I can average over 19 mpg on a full highway tank with 91 no ethanol. The 92 with 10% will do about 17 in the same conditions.
I would love to see the timing maps for an 06/07 LC vs 06/07 LX to see if that “Premium Required” is actually being taken advantage of. They could have just as easily said “Premium Recommended” but they chose “Required” for a reason on the LX. Two very different labels.