IS 250 Exhaust system material, mild or stainless steel ?

[bernieeccles]

As someone on the lookout for my "perfect" IS 250, I have been reading the manufacturers past brochures online and the 2008 to 2010 all describe the exhaust system as being stainless steel.

Yet, I have looked under the rear of a few older models and the rusty appearance would suggest they are mild steel.

Is there a date from which, the car definitely came with stainless exhausts.

 

Thanks.

[Linas.P]

There were no stainless steel exhaust in UK on any mk2 IS.

Maybe you were reading US brochures where they were fitting aftermarket cat-backs in dealerships from (I believe) HKS?

As well check out previous posts - you better avoid SS mid section as it does result in drone. On other hand IS exhaust is prone for rusting and genuine one costs silly money (~£3000).

My suggestion would be to get car with stock mild steel exhaust and get SS back section if you want more "noise" and as well because it is the bit which corrodes most.

[Brechin Slate]

Sort of relevant, hopefully helpful:  2 weeks ago I noticed a blow from my exhaust so got the local garage to put it on the ramp.  The weld had started to go around where the rear pipe divides before entering the 2 back boxes.  Apparently I was looking at £700 for a stainless steel replacement.  I paid £179 from an online company to supply the rear section from the 2 bolt flange backwards.  The one that came off was original (Jan 2007) and the weld and adjacent pipework were rusted through so assuming either mild steel or low grade stainless.   Having said that, 10 years from an exhaust system seems ok to me.

[bobmc]

You're right, the 'Nov 08 brochure specifically mentions that the IS250 has a stainless steel exhaust, as does the '09 and '10 brochures. This feature isn't mentioned in the '07 brochure so perhaps this was just from late 2008 onwards?

Good luck with your search   

[dougie175]

My 2010 F-Sport is made of mild steel, as far as I know none of the IS250's came with SS from factory

[Linas.P]

Maybe SS tips... that would be as much SS as you can get from factory. 

[dougie175]

1 minute ago, Linas.P said:

Maybe SS tips... that would be as much SS as you can get from factory. 

Agreed yeah I do have the tips but they I think all IS250's from first manufacture came with SS tips so nothing different about later models to early ones

[Britprius]

If the GS is anything to go by the pipe work is not stainless. The rear silencers have stainless end plates and a "very" thin stainless outer cover. This gets eaten away by by sulfuric acid from the combustion process eventually from the inside. 

See my pictures in the GS section under "Exhaust problems".

John.

[Linas.P]

Exactly, you are right all IS250's came with SS tips. Where IS220d had standard diesel pipe, but I have never head of full SS, or even SS back sections.

[bernieeccles]

The online brochure has a Lexus UK address in some of the blurb and here is the wording.

"And it's built to last: features such as a chain-driven valve system mean your valves will never need adjusting, and a stainless steel dual exhaust system reduces corrosion and keeps noise to a minimum"

That sentence is contained in all three brochures 2008 to 2010.

If that's not true, then that is/was false advertising surely. Lexus couldn't claim a printing error in three different yearly brochures so what was going on.

Brochures here.

https://www.lexus.co.uk/owners/your-lexus/#PastLexusBrochures?utm_source=LexusOwnersClubUK&utm_medium=ForumLinks

[normski2]

Mmmmmmmm ..... Interesting.

I've only ever known of mild steel in mk2 IS's

Mine is 2010 and its mild steel from what I can see.

[Britprius]

Being stainless does not stop the exhaust "in particular the silencers" from being eaten away by acid.

The silencers are more vulnerable because the metal is thinner, they run cooler and have areas below the pipe levels that cannot drain moisture. Once the inner skin gets perforated the acid moister gets trapped between the two skins attacking the inner skin from both sides.

John.

[dazed]

Both of my mk2 ISes (2007 and 2012) had/have steel exhausts.

[Linas.P]

53 minutes ago, bernieeccles said:

"And it's built to last: features such as a chain-driven valve system mean your valves will never need adjusting, and a stainless steel dual exhaust system reduces corrosion and keeps noise to a minimum"

That sentence is contained in all three brochures 2008 to 2010.

I am wondering... maybe they had something like SS inserts in certain parts e.g. silencers. From outside it is definitely mild steel, most pipes are single wall and it is mild as well. Around mid section there are some guards, but they seems to be aluminum foil type of material probably like 0.125 -0.25 mm.

I know that quite well, checked that under the car today, because I am certain there is hole somewhere in my exhaust, but could not locate where it is.

[bernieeccles]

48 minutes ago, Britprius said:

Being stainless does not stop the exhaust "in particular the silencers" from being eaten away by acid.

The silencers are more vulnerable because the metal is thinner, they run cooler and have areas below the pipe levels that cannot drain moisture. Once the inner skin gets perforated the acid moister gets trapped between the two skins attacking the inner skin from both sides.

John.

That's as maybe, but it is widely recognised that a stainless steel system will outlive a mild steel one by many many years.

An oft used phrase contained in Lexus advertising is "The pursuit of perfection" A cheapo mild steel exhaust, especially one that costs, what did someone say? £3000 to replace seems to suggest that they need to pursue it a bit harder.

[Linas.P]

To be more precise, rear section is something like £680+vat and mid part is is like £2700+vat, so it is closer to £4k.

I completely agree that it is not fair to advertise it as SS if it is mild - I was not aware about this.

But, just to be clear there is nothing wrong with standard mild steel system. Yes if you looking for 8-10 years old car it will have some rust, but to be honest any car similar age will have rust on exhaust. I believe mild steel was chosen to make it quieter (SS drones). So actually if I would be looking for used IS250 to buy I would better choose one with OE mild steel system which will have some rust, than aftermarket SS system which will drone all the time. My point both SS and Mild has their own advantages and disadvantages, but it is not like SS is outright better just because it is SS.

Obviously, everyone has their own priorities. 

[Brechin Slate]

Agreed re the drone but there is a fairly hefty anti drone damper fitted to the n/S silencer box. The fibre bushes broke when I removed mine but plumbers fibre washers were a good substitute

[bernieeccles]

Yes, I agree that there is nothing wrong with mild steel for an exhaust but Lexus are possibly misleading buyers. I have sent off an email to Lexus UK querying this point and will be interested to see if they reply and what it might be.

So, £4000 for a mild steel exhaust ? Even taking into account the relative small numbers of these cars sold, that figure is just a ***** take. There is no way on Gods earth that I would pay that. I reckon at the very worst a new system could be made by cutting off silencer boxes from another make exhaust and welding sections together to make a new system at a fraction of that cost.

I wonder if anyone on here has tried doing that ?

 

 

[Linas.P]

I didn't say anyone ever bought it for nearly £4000, but that is cost of OE part. For fraction of the costs you can but full custom system (£400-500) or even quality aftermarket one (£800).

I guess when the car was new @ £35000 the cost was fine, when now car itself costs £4000-5000, the new OE replacement system costs seams astronomical. It would make sense if Lexus would make like 80% of on these systems to make them comparable to the car, but I guess they rather keep them at priced as is and encourage people to upgrade.

For example when they tell me or you after the service that corroded exhaust needs to be changed for £4000 we would just laugh in their face, but some other person who know nothing about the cars would be lured into PX and upgrade, because sales man would say something like: "we can PX your car for £4000 + costs of your exhaust fix £4000 and you you woudl need to add only extra £2000 and have something 5 years like IS300h. So do you want to spend £4000 on just fixing your old car exhaust or you rather spend £6000 and get much never car with less issues".

I personally consider that standard MS system lasted well on my car (now over 160k miles and 8 years) and if would need to fix it I would just replace it with custom MS mid section and custom SS back section all in all maybe £700 with fitting.

[is200 Newbie]

1 hour ago, bernieeccles said:

Yes, I agree that there is nothing wrong with mild steel for an exhaust but Lexus are possibly misleading buyers. I have sent off an email to Lexus UK querying this point and will be interested to see if they reply and what it might be.

So, £4000 for a mild steel exhaust ? Even taking into account the relative small numbers of these cars sold, that figure is just a ***** take. There is no way on Gods earth that I would pay that. I reckon at the very worst a new system could be made by cutting off silencer boxes from another make exhaust and welding sections together to make a new system at a fraction of that cost.

I wonder if anyone on here has tried doing that ?

 

 

Done just that - The exhaust on mine failed at around 70k - a few years ago. I could not find a replacement as the pattern part is not released by Lexus to the likes of ATS etc.. so going down the road in asking Lexus to replace it, considering its the only supplier that had the ability to do so with an OEM supplied part, this would have costed close to £3k (£2700)and that was a few years ago !!

I could not justify that so I went down the route of a stainless steel exhaust at £350. It was awful (drone between 2 to 2.5k revs). I put up with it for a few years then decided to make my own. Spent a lot of time finding suitable parts and looking into the compatibilities for pipe sizes etc.

Went with the mild steel option as its best material between the steel options for absorbing the noise the exhaust creates. Went with slightly bigger pipe between the resonator and the boxes and went with Rover ZT boxes (twin outlets on each) as they were a perfect fit into the under body recess .So I made the centre piece, the resonator all the way back to the boxes and fitted the Rover boxes.

The only issue I had was with a bit of welding (one persistent leak) - never welded before but by the time I had finished it was pretty good. In making it myself it cost around £150. I bought a MIG welder in that cost also. I have made the exhaust in a way that the sections can be replaced easily if / or rather when, it rusts through which isn't an issue as I found it an easy job.

It was MOT'd this year and passed. Exhaust has been on just over a year and a half (EDITED - Has been on car for almost a year - not a year and a half !). I will quite happily keep it on and would recommend the mild steel option for two reasons: its easy to use, both bend and weld with no professional tooling and its quiet when the cars running.

[bernieeccles]

That sounds good. Did you have to replace and fabricate the pipe that splits into two at the rear to feed the two back boxes ?

[is200 Newbie]

2 minutes ago, bernieeccles said:

That sounds good. Did you have to replace and fabricate the pipe that splits into two at the rear to feed the two back boxes ?

Everything from the resonator (including the resonator) back was replaced - the y piece pipe was not that hard as I had the old one to use as a template but must admit that was where I had the persistent exhaust leak but eventually found and welded it shut.

Picture is of the Rover box used and the finished look on the car.

 

[bernieeccles]

Update.

After sending a query to Lexus UK, this is the first reply I got.

Thank you for your email.

The Lexus IS250 exhaust system was made from Steel, not stainless steel. 

So that I can look into this further, please can you reply to this email with a link or a print screen showing where you saw this information.

I apologise for any inconvenience that this has caused. 

Kind regards 

Olivia

Olivia Lewis
Lexus Customer Services

-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

After my reply and direction to where the quote could be found, I received a second reply.

-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Thank you for your enquiry regarding the specification of the exhaust on IS 250 2008-2011.

I've checked the information in the brochures pertaining to the exhaust and also clarified the original respones you were provided.

The brochures are correct in that all Lexus exhausts are made of a steel grade which meets the criteria to be called stainless steel.  There is a spectrum of steel ranging from mild steel to high grade stainless steel and our exhausts fall within the upper quartile.

There is sometimes a perception that for an exhaust to be called stainless steel it has to have a chrome like finish, this is incorrect.

It is also worth checking if you buy a used vehicle that the exhaust has not at any time been replaced with an inferior product.

I trust this clarifies the matter for you. 

Kind regards

 

Jenny Shipley
Customer Relations Case Manager
Toyota (GB) PLC - Lexus Division
Distributor of vehicles, parts and accessories for the UK

So, should a steel that is classified as being stainless (ambiguously in my opinion) rust ?

 

[Monocle]

I know very little about exhausts and the types of steel used in exhausts but, remembering back to my college days (a good while ago!), there is a broad range of steel grades across generic groupings like mild, stainless, etc. The first thing we were told is that stainless does rust, just less, and in some cases can be magnetic. The one thing I do remember is that for a steel to be classed stainless, it has to have a minimum level of Chromium. 10% or something like that. 

It can be very hard to tell the difference between mild steel and a low grade stainless steel especially if it hasn't been polished and has been through the rigours of high temps, moisture and acidity. 

[Linas.P]

The above points are true, but to be honest I don't think it matters. The problem here is that on some marketing material Lexus called something stainless steel specifically implying it will be more robust when exposed to elements, which is not the case and outright lie.

I personally don't think that reduces the value of the vehicles or impacts experience in any way. Reliability, of mk 2 IS250 auto (specifically not manual and not diesel) is second to none (ok maybe mk1 LS400)... and mild steel exhaust last over 8-10 years and well over 100k miles, which is approximately just above average for ICE cars.

So it is bit mixed message - Lexus lied in their marketing material ... shame on them, yet does it really matter, does it make car worse than peers in segment - definitely not.