What specifically makes the 2005-2008 models unsuitable for E10 fuel?

[catnap]

[Linas.P]

Lol imagine is that is the only thing you need to make your car E10 compatible.... would be silly isn't it?

The other thing to note, from my experience in older cars fuel hoses and other things that are submerged often do not fail before you take them out i.e. one day you think "maybe I am going to change strainer on fuel pump", and you only realise it is very brittle when you try to take it out, or soft and deteriorated. Point being - it is entirely possible that I was driving on E85 for 20k miles completely fine and nothing failed... and I could have driven another 50k miles and all be fine, but the "damage" would only manifests itself when taking fuel system apart in a form of harder, softer, more brittle parts than they should be. 

[catnap]

42 minutes ago, Linas.P said:

Lol imagine is that is the only thing you need to make your car E10 compatible.... would be silly isn't it?

The other thing to note, from my experience in older cars fuel hoses and other things that are submerged often do not fail before you take them out i.e. one day you think "maybe I am going to change strainer on fuel pump", and you only realise it is very brittle when you try to take it out, or soft and deteriorated. Point being - it is entirely possible that I was driving on E85 for 20k miles completely fine and nothing failed... and I could have driven another 50k miles and all be fine, but the "damage" would only manifests itself when taking fuel system apart in a form of harder, softer, more brittle parts than they should be. 

Wouldn't it just! I can see plastic and rubber being corroded or eaten by ethanol so maybe that's all that's needed. Certainly that's all I can see being changed in 2007.

Noted about the rest. I need to get the older 300 up and running first, then I'll look to "convert" this one and inspect the pump thoroughly for any wear when it's out of the tank. I might even get some E85 and leave those bits sitting in it to see if they fall apart. That also gives me the time to order replacement bits from Amayama if I need them.

[Texas]

Excellent work that man, top of the class and all that 👍

[Texas]

So….,,,been thinking about this and if ( and it’s a BIG if) the only component that Lexus cannot/will not guarantee is compatible with E10 is this ‘O’ ring seal ( caveat: there may be other components) then what would be the likely consequences of if failing?
Catastrophic fuel failure due to loss of fuel pressure from pump?

Or a slight loss of fuel pressure only noticeable under maximum demand from pump? 

and ( I don’t know exactly ) where this ‘O’ ring lives and what it’s purpose it serves.

just looked it up and it appears to be pump to fuel tank sealing ring itself !

So would not affect the running of the car itself but if compromised could allow fuel/vapours to be released from fuel tank under rear passengers seats
😳

And as for dealer stating there is no way to make it compatible!!! If it is this seal ( only) then REALLY!🙄 I know they want yo sell new cars but 🤯

 

 

[catnap]

2 hours ago, Texas said:

So….,,,been thinking about this and if ( and it’s a BIG if) the only component that Lexus cannot/will not guarantee is compatible with E10 is this ‘O’ ring seal ( caveat: there may be other components) then what would be the likely consequences of if failing?
Catastrophic fuel failure due to loss of fuel pressure from pump?

Or a slight loss of fuel pressure only noticeable under maximum demand from pump? 

and ( I don’t know exactly ) where this ‘O’ ring lives and what it’s purpose it serves.

just looked it up and it appears to be pump to fuel tank sealing ring itself !

So would not affect the running of the car itself but if compromised could allow fuel/vapours to be released from fuel tank under rear passengers seats
😳

And as for dealer stating there is no way to make it compatible!!! If it is this seal ( only) then REALLY!🙄 I know they want yo sell new cars but 🤯

 

 

Actually it's the seal at the bottom of the fuel pump basket assembly so you'd be quite safe if it failed. It might disintegrate and you'd get a reduction in pumping volume but you'd never get fuel in the cabin. The other component is the plastic basket that the fuel pump assembly sits in. If you watch a video on YouTube about replacing a fuel pump, it's usually white in colour and is the thing that comes out when you pull the assembly out, with the pump, hoses and fuel level sender attached to it. So if that fails then I suppose the pump could become disconnected or similar.

 

I did find the dealer's response a bit hilarious. Plus as I said, he "checked with his service advisor" a little too quickly so I think he wanted me off the phone haha.

[Spark plug]

I'm sticking with bp super 97 e5, seems to run better and does a few more miles to the gallon 

[catnap]

"Thank you for your prompt response.  We have consulted with some of our internal technical specialists who have advised we simply do not have access to the relevant technical detail you require.  May I suggest you also discuss your requirements for a technical specialist at your local Lexus Centre who may have a more qualified opinion?

I am sorry I am not in a position to provide more clarity on this particular query."

 

Lexus UK really aren't interested in sharing any info it would seem! Oh well.

[Texas]

No surprise there! Just as I expected, only a bit more ‘Flowery’😂

[catnap]

53 minutes ago, Texas said:

No surprise there! Just as I expected, only a bit more ‘Flowery’😂

Maybe I should offer my services as a "technical expert" 🤔

[Mr Vlad]

Yup sounds like they're covering their bottoms on this subject for fear of customer reprisals. 

[MrTrendizzle]

From being unable to read the "Not compatible" list correctly i've been using E10 in my 2007 (56 plate) IS250 without any problems at all. Honestly mentally i notice a lack of grunt but that's just in my head as no-one else has mentioned the car not being as spunky as it was before.  

I fully expect to be changing some rubber tubes/gaskets at some point which is neither a big cost or huge job to do. Be it fuel pump, fuel line or popping the injectors out to replace their rubber parts. I'm sure it was Texas who pointed out my inability to read and linked a rubber o ring that would be the cause of failure. (I'm to tired to look through my history to find it)  

Like others have said. If a Lexus is built to last 100k miles they fully expect all the rubber seals to last that long. So if E10 degrades that rubber by a few years and that rubber breaks down at 99k miles people would be knocking on Lexus door's for a full engine rebuild or the very least a free part and fitting.  

I've done some chemical analysis with E10 and it's not much different. Gas emissions change a fair bit for the worse imho. Imagine swapping out CO2 for NOX etc... while you might think awesome less CO2 they fail to mention the higher NOX levels and if you really dive in to it. Tree's and plants love CO2 but hate NOX while Humans hate everything. So by lowering CO2 emissions everything think's they're saving the planet...  

Anyway E10 won't degrade rubber to the extent you can really worry about it. Considering 5% vs 10% is a very small percentage (Put it this way. 100L of fuel contains 10L of ethanol. When mixed it does very little to change the effects) Over a long period of time yes it will break down rubbers it comes in contact with but your car which lets say is on 60k miles is due some repairs before the rubber even thinks about breaking down.  

I still use E10 and from time to time i'll chuck in a full E5 tank with some Redex or other fuel system cleaner/lube.

[catnap]

I've noticed a mild MPG increase but that might simply be because I'm being extra careful. Last night I put 56L in for a grand total of £107 which made me wince at the pump. I'm now logging in Fuelly to see if there's a significant change or not.

One thing I do need to do is keep an eye on the knock correction learned values in Techstream which indicate if the car's happy with the fuel type and advancing the timing as far as it can. The lower-grade E10 fuel might force the car to retard timing a bit, losing a small amount of power. Apparently a few wide-open pulls to redline are enough to update the value automatically.

Agreed about E10 being a bit of a useless "fix" to the perceived problem. It sounds political so don't get me started on that. My wife works for a fuel company (local to the South East) and some of the senior people there have opined that E10 doesn't make a blind bit of sense. They were offering E0 as their standard which attracted a lot of classic car users, but once the summer's over they may not be able to supply it anymore as it's getting unprofitable for them. I think they have one tanker's worth to get through then they'll have to make a decision. Shame really as I was relying on that fuel to keep me going!

[Texas]

So is Ethanol gonna turn out to be a false good ( like Diesel!)

 

[J Henderson]

21 hours ago, MrTrendizzle said:

I notice a lack of grunt but that's just in my head as no-one else has mentioned the car not being as spunky as it was before.

I noticed it.

Car felt significantly worse to me running on E10, so switched back to using E5. Then, after a number of tankfuls, decided to give E10 another shot to see if it really was as bad as I remembered....Yes, yes it was so that was the last time I bought E10.

As long as E5 remains available (and my fear is that it won't be around much longer), I'll continue to pay the small premium for it, despite my car being approved to use E10.

[BC99]

On 6/7/2022 at 6:42 PM, Texas said:

So….,,,been thinking about this and if ( and it’s a BIG if) the only component that Lexus cannot/will not guarantee is compatible with E10 is this ‘O’ ring seal ( caveat: there may be other components) then what would be the likely consequences of if failing?
Catastrophic fuel failure due to loss of fuel pressure from pump?

Or a slight loss of fuel pressure only noticeable under maximum demand from pump? 

and ( I don’t know exactly ) where this ‘O’ ring lives and what it’s purpose it serves.

just looked it up and it appears to be pump to fuel tank sealing ring itself !

So would not affect the running of the car itself but if compromised could allow fuel/vapours to be released from fuel tank under rear passengers seats
😳

And as for dealer stating there is no way to make it compatible!!! If it is this seal ( only) then REALLY!🙄 I know they want yo sell new cars but 🤯

 

 

I had an issue in that area last year, It caused a fairly large petrol leak, which is an obvious fire risk, it started with a faint smell of fuel which i couldn't locate, and ultimately progressed. In my case i think it was caused by the steel retaining ring rusting, which put pressure on the top of the plastic pump and it cracked.

The list of cars affected seem to almost exclusively be early direct injection vehicles, so i would have thought the issue would lie in the high pressure fuel line areas, rather than the low pressure parts. If it was just the electric pump in the tank and it's gasket, it would be incredibly simple to fix, albeit the pump would be costly if not secondhand.

[Alfalfa]

On 6/10/2022 at 5:29 PM, J Henderson said:

I noticed it.

Car felt significantly worse to me running on E10, so switched back to using E5. Then, after a number of tankfuls, decided to give E10 another shot to see if it really was as bad as I remembered....Yes, yes it was so that was the last time I bought E10.

As long as E5 remains available (and my fear is that it won't be around much longer), I'll continue to pay the small premium for it, despite my car being approved to use E10.

I use 98 octane.

[MartinH]

9 hours ago, BC99 said:

The list of cars affected seem to almost exclusively be early direct injection vehicles, so i would have thought the issue would lie in the high pressure fuel line areas

That is my understanding too — corrosion likely to form (eventually) within these components when E10 fuel is used

[catnap]

19 hours ago, BC99 said:

The list of cars affected seem to almost exclusively be early direct injection vehicles, so i would have thought the issue would lie in the high pressure fuel line areas, rather than the low pressure parts. If it was just the electric pump in the tank and it's gasket, it would be incredibly simple to fix, albeit the pump would be costly if not secondhand.

I'd caution against this correlation being pointed to as a cause, as the high pressure fuel pump (and all parts connected to it) are not listed as having changed in 2007. There was a revision in 2006 but this doesn't match up in the timeline and is likely a very early part revision for the first run of the cars:

Only the two parts I posted are showing as having had revisions in 2007, specifically October.

It's entirely possible that it's only the type of plastic used for the pump basket and the associated gasket material not being up to spec for withstanding E10, but I don't want to call this discovery a fix or the definitive answer to this question. There may, of course, be things that changed that aren't listed but I can't verify that.

 

[Edit] To add- the in-tank pump itself did not see a revision. It's the plastic basket that contains the components within the tank that was revised- linked in a previous post.

[mafio]

Hi can I add my bit to this discussion. I have 2010 IS 250 my local garage only has E10 so I have been using this for some while with no obvious effects. A 200mile trip down the M1 averages about 40 mph around town about 30mph.

The paragraph below was taken from Wikipedia  'Ethanol Fuel'

Ethanol contains approximately 34% less energy per unit volume than gasoline, and therefore in theory, burning pure ethanol in a vehicle reduces range per unit measure by 34%, given the same fuel economy, compared to burning pure gasoline. However, since ethanol has a higher octane rating, the engine can be made more efficient by raising its compression ratio.

My guess on why pre 2010 cars are not suitable for E10, is that on 2010 cars the compression ratio has been raised to compensate. However on pre 2010 cars with a lower compression ratio the published fuel consumption figures wouldn't be correct when using E10, therefore opening up a can of worms for the manufacturers.

 

[Spock66]

59 minutes ago, mafio said:

A 200mile trip down the M1 averages about 40 mph around town about 30mph.

MPG?

[mafio]

Sorry mpg. 

[catnap]

2 hours ago, mafio said:

My guess on why pre 2010 cars are not suitable for E10, is that on 2010 cars the compression ratio has been raised to compensate. However on pre 2010 cars with a lower compression ratio the published fuel consumption figures wouldn't be correct when using E10, therefore opening up a can of worms for the manufacturers.

 

October 2007 and onwards IS250s are able to use E10 and the compression ratio hasn't changed between these.

[Thelongterm]

On 6/16/2022 at 1:13 PM, catnap said:

October 2007 and onwards IS250s are able to use E10 and the compression ratio hasn't changed between these.

Am I correct that the biggest selling years for the IS (petrol and derv) are 2005 to 2008?

This will make a very big chunk of the running stock needing to drink E5, I wonder how many are even aware.

[catnap]

On 6/24/2022 at 4:50 PM, Thelongterm said:

Am I correct that the biggest selling years for the IS (petrol and derv) are 2005 to 2008?

This will make a very big chunk of the running stock needing to drink E5, I wonder how many are even aware.

I don't know actually, though I did a Freedom of Information request to the DVLA for numbers of the previous generation of cars as I was curious how rare my green 300 Sportcross was (turns out; quite rare) so I might do one for the 2nd generation in the future. But yes, good point. I wonder if the 220d was as affected by E10? I don't even know if they put E10 in diesel.