Is the damage already done?

[Mrlebrun]

I have been thinking about getting an is250 2007 model and I am aware that they have to be run on e5 fuel due to issues with e10, if the person has been running the car on e10 for about a year sometimes using e5 but not very often is the damage already done or if I bought it and only used e5 would it be OK? 

[Linas.P]

I have always run mine on E10, even E85 and there were never any issues. Majority of Europe that has E85 as default cheapest fuel would be as well running these cars on E85 and there is no widespread reported issues. So at least in my opinion your worries are unfounded.

One member here looked trough the list of all parts and found that difference between pre 2008 and post 2008 models are few o-rings that costs like £2 and £6 respectively, the rest of parts are identical and Lexus advises that 2008+ can run E10. As well that is not to say those o-rings are the reason, just that they are only different part in fuel system between compatible and incompatible cars.

I think people are just being too sensitive about it. When living in another country I have always used E85 and didn't even know there could be an issue, nobody knew, we simply never had big switchover, E85 was simply much cheaper and that is what everyone used... although back then I had 2012 IS250. But even now when I go to France for example I just get E85 and I was doing it for tens of thousands of miles.

Either way - you get my point, if E85 does not cause issues, then I can't see how E10 can cause issues with 7-8 times lower ethanol content. The only thing about E85, you should not leave it for long time in the tank, because it absorbs water. To some degree same applies to E10, if you could leave pure petrol in the tank and it would still be good after 12 months, then E5 is probably only good for 6 months, E10 for 3 months and E85 for 1 month.

To answer your question shortly - nobody knows if damage would have been done, because nobody have ever seen ethanol causing damage to these cars. 

[Sundance]

Daniel, there is absolutely no way of telling.  As reports suggest that E10 accelerates wear on certain parts within the fuel supply system (eg fuel lines, seals, gaskets etc) then how is anyone going to know without taking the system apart?

When I sold my IS250 (06) the buyer asked no questions about fuel use so for all I know may well be running it on E10 not realising that I had attempted to mitigate any potential damage risk by using E5. The opposite view to your situation.

This E5/E10 business is made even more difficult because despite there being multiple recommendations not to use E10 on so-called non-compatible vehicles there seem to be few reliable references that illustrate without doubt the categorical consequence and damage that has been proven as a result of misuse.

[Spock66]

2 hours ago, Sundance said:

This E5/E10 business is made even more difficult because despite there being multiple recommendations not to use E10 on so-called non-compatible vehicles there seem to be few reliable references that illustrate without doubt the categorical consequence and damage that has been proven as a result of misuse.

I am thinking if E10 is bad for a car then by definition E5 must be half as bad, or take twice as long for the problems to manifest.

[Linas.P]

3 hours ago, Spock66 said:

I am thinking if E10 is bad for a car then by definition E5 must be half as bad, or take twice as long for the problems to manifest.

Pretty much exactly that...

But then if E5 was bad, then me using E85 should have blown everything in an instant! and yet I have probably like 40k miles on the stuff!

[Neilo]

I thought the same thing when I bought my 06 last December - has the previous owner been using E10 only.

It's been fine, no disasters and running lovely with E10 + Millers EPS additive.

Time will tell I suppose but it's not at the top of my worry list.

Best wishes

   

[MrTrendizzle]

I run my 2006 IS250 on the cheap stuff.  

If it destroys some rubber gaskets or hoses then i'm ok with that as they would've needed replacing soon anyway. But since the E10 came out i've ran it on E10 and honestly the only couple of things i could possibly say is the lack of power. E5 just seems like it has more pep in its step compared to E10 and the millage on E5 seems to be far better than E10.  

My weekly round trips to school and back i get an average of 24mpg = E10 vs 28 = E5  

Same with motorway driving 34 = E10 vs 39 = E5  

For an MOT i'll chuck in a bottle of injector cleaner and cat clean before running empty and filling up with E5. Emissions all passed well within limits except lambda which was 1024 a tad close to the max pass but it passed while HC etc... was exceptionally low. 

Like i said tho if E10 destroys some rubber hose/gaskets it's a cheap fix and the new rubber/gaskets will all be rated for E10 regardless so it's not really an issue. I'm sure there's been a huge thread on what exactly is the cause of the E5 only rule and if my memory dosn't fail me it was something to do with the fuel pump gasket that E10 can cause it to deteriorate and leaking fumes in to the cabin is a big no-no for Lexus but the part number to replace it is the same for both E10 and E5 rated vehicles so the rubber compound has likely been updated over time which is why 2006 vs 2008 cars are rated differently for example.

[Linas.P]

That is exactly what I would expect to see - 3% difference in economy/performance split in half between slight performance reduction and slight mpg reduction. In practice it is probably more than 3%, but it is not significant to worry about.

I am in pretty much same mind as above... sure E10 may ruin your fuel pump over time, but on 10+ years car fuel pump is likely to go anyway and replacement pump (especially if it was already replaced) will have seals with new compounds.

E10 does not hurt engine, injectors etc. In fact ethanol itself could be used as additive for engine cleaning, so it does not hurt any mechanical parts of car. Rubber hoses apparently are not an issue, because they have not changed in 2008+ cars despite them being compatible.

[Mr Vlad]

Well Daniel what gave you decided on?

I hope you haven't been put off getting an is250 just because of the petrol situation.