Do automakers ECU-tune their motors to make new models and versions?

Question

I am considering ECU tuning my car (landcruiser 150 2.8 D4D) and have been reading about the issue. Someone told me that automakers frequently use the same motor across models and versions, yet it ends up having different power. This seems to indicate that the motor in question had enough reserve to be tuned for more power. After all they can't just make new motors for every car version.

How sound is this analysis in the case of landcruiser 150 2.8 D4D 177hp?

I bought this car for 50k€ brand new in 2020 (called executive, 2018). When I now go on Toyota's official website in my area (toyota.bg) I see the "new" Landcruiser version, called "special edition", which costs 50% more than what I paid brand new and has 204hp instead of 177 like mine and the motor is still 2.8 D4D it seems and everything else looks exactly the same.

It makes sense, that in an effort to hide inflation, they are reselling the exact same car but tuned a bit differently.

If that is the case, why shouldn't I tune my car from 177hp to about 220hp (which is what the tuning person in my area recommended as a safe tune that's not going to cause issues)?

If Toyota didn't simply update the ECU to give this motor more power, but also did other light changes, what might those additional changes be?

I doubt that they have changed anything major, the landcruiser is on its last legs and won't be produced in the future from what I read.

Answer 1

It's absolutely true that auto manufacturers tune engines to give different performance levels. I had a BMW 530d and discovered it was the same engine as the 535d, the only difference was the programming. Whether the engine is the same in your specific case I cannot say for sure, although it's entirely possible.

Sometimes an auto-maker will offer more power for the same exact specs of everything else, although sometimes there are other upgrades other than trim, for example:

• Brakes: a 25% increase in engine power and higher top speed may need to be offset by more effective brakes. If the car is going to be more sporty you may have chunkier calipers and rotors, or vented rotors
• Tires: a significantly higher top speed may need higher speed rated tire, or bigger profile tires
• Transmission: more power or torque may call for a different transmission, or different programming on the transmission computer. These mappings are also often available
• Suspension: more performance may need stiffer suspension or beefier roll bars
• Exhaust: more power means more fuel burn and emissions, which may need a different exhaust to comply with emissions regulations
• Air intake: more power needs more air, which may mean a bigger air intake

As for your car, it's likely Toyota has made some tweaks between the model years, in order to understand how much of the above applies would require some research on your part. If it's a well-known remap you'll probably be fine. Just remember to check with your insurance company, remapping may mean an increase in your premium.

Answer 2

How sound is this analysis in the case of landcruiser 150 2.8 D4D 177hp?

I think it is very sound. @GdD has very valid points. The thing to remember with turbocharged engines, especially diesel powered ones, it is very easy to just "turn it up" a notch or two.

There are two different ways programmatically to increase the horsepower in almost any engine.

The first way is to allow the engine to rev higher. Given that horsepower in and of itself is just mathematically derived from torque at any given engine speed (work over time), all you have to do is allow and engine to spin higher and it can produce more horsepower. Here's the formula:

There is a point where the friction produced inside of the engine will limit the amount of power which can be produced.

The second way is to allow the turbocharger to produce more boost. With more boost, you add more fuel, and bang, you've got more horsepower (and torque for that matter). As long as the turbocharger which is installed can support the added boost levels, it's relatively easy to make more power. I'm sure this is the route your tuner and everyone else takes to bring your 177hp up to the 220hp they quoted.

If Toyota didn't simply update the ECU to give this motor more power, but also did other light changes, what might those additional changes be?

Minor things internal to an engine could have been done to allow for greater horsepower. Two things which come to mind are the cam(s) and static compression. Either one of these, though, would require a different tune from the manufacturer. Realistically, it doesn't cost the manufacturer any more in materials, assembly of the engine, or vehicle assembly to make these changes. There are added engineering costs, but those are a given with ever tightening emissions standards. Manufacturers are always looking for ways to make an engine produce more power while emitting fewer pollutants. Unless you are aware of the nitty-gritty of how an engine is built, you really wouldn't know if something was changed from year to year. Some manufacturers release the specs of engines, while others don't. Just one of those things.