[Basterma]

If I unlock my 2023 m340 ecu and start tuning, that will void the warranty. When I want to sell the car in 2 years, will BMW take the car back? Will I be able to sell it to another 3rd party dealer or carmax? Just questions I am considering for the longterm to know my possible outcomes.

[relentlessone]

In my experience shopping for an M340, I found that BMW dealers send tuned cars to auction. I found a couple 2020's in my search that had just been traded in, only to find they were being sent to auction due to "suspicion of tuning". I can't say for sure about third party dealers.

[mike@x-ph.com]

keep your stock parts, so you can re-install them. its easier to sell it this way and you can sell your aftermarket parts on here and get some of your money back

[Kimnation]

ik a guy who ran port injection + e85 stage 2 bm3 on his leased g80 and he turned it in to the dealer with no issues (don’t try this lol). I think in general most dealers are okay with it as long as everything has been put back to stock and u didn’t cause any damage/premature wear, but it really depends on the dealer because i’ve heard of people getting fined too.

TLDR: tune should be fine but ymmv

[prostcfc]

Definately hold on to stock parts if you have the space to do so. The benefits later on outweigh getting some cash up front. Regarding tuning, BMW dealers with ISTA will generally be able to tell if you did it and flashed back to stock (S0777 fault), but 3rd party dealers probably could not since they probably don't have ISTA; so flash back to stock.

[Panscan340]

Originally Posted by Kimnation

ik a guy who ran port injection + e85 stage 2 bm3 on his leased g80 and he turned it in to the dealer with no issues (don’t try this lol). I think in general most dealers are okay with it as long as everything has been put back to stock and u didn’t cause any damage/premature wear, but it really depends on the dealer because i’ve heard of people getting fined too.

TLDR: tune should be fine but ymmv

By definition this configuration would result in premature wear on the drivetrain , and this guy is a scumbag

[F32Fleet]

Originally Posted by Panscan340

By definition this configuration would result in premature wear on the drivetrain , and this guy is a scumbag

Plenty of those around.

[VegasG42]

Originally Posted by relentlessone

In my experience shopping for an M340, I found that BMW dealers send tuned cars to auction. I found a couple 2020's in my search that had just been traded in, only to find they were being sent to auction due to "suspicion of tuning". I can't say for sure about third party dealers.

So typically does the BMW dealership take the trade and give you their full value like they normally would ?

Or when inspecting the car, do they see that the car had a tune, and offer you significantly less ?

[totalone]

Originally Posted by VegasG42

So typically does the BMW dealership take the trade and give you their full value like they normally would ?

Or when inspecting the car, do they see that the car had a tune, and offer you significantly less ?

I dont think they actually connect to read off codes. I think they just inspect, to make sure its drivable and there are no subnormal sounds etc..

[drwankel]

Originally Posted by Basterma

If I unlock my 2023 m340 ecu and start tuning, that will void the warranty. When I want to sell the car in 2 years, will BMW take the car back? Will I be able to sell it to another 3rd party dealer or carmax? Just questions I am considering for the longterm to know my possible outcomes.

You are in california. You cant pass emissions with a tune, as a tune on the DME will fail the scan, because it will not match the CRC check of the stock tune.

A dealer can be sued if they sell a car that cant pass emissions.

They may not offer to buy your car back at all, or if they do offer to buy it back you can bet they will offer you less than a stock car.

Mods generally lower the value of any car, and on the m340, its almost a certainty. Even without a tune, they wont be able to sell a modded car for the same price as a stock car, so they will most certainly offer you less than if it was stock.

If you plan on modding it, and do not plan on keeping it long, make sure you have a plan to return it to stock before you sell it.