Mercruiser 4.5L 200 and 4.5L 250 - any word on the real difference? Opinions?

[bobbobobbo]

I'm looking at a VR5 and trying to decide whether to grab a local model with the 4.5L 200, or order in and wait for the 250. I certainly want the extra power (who doesn't) yet I'm curious if there will ever be an easy upgrade.

I emailed the guys at magnum tuning about their chip upgrade, yet no response yet. They have an identical chip, tune, map and everything for that works on the 200 and 250, so I was curious if using a chip would bump it to 250, and then some. As it appears that the stock 250 only has a different "tune" coming from the ECU vs the 200.

http://www.magnumtuning.com/en/detai...er/4-5l-250-hp

Yet then again... I'm not sure how Bayliner/Merc can ask for $4k more for the 250 engine if it's really just the difference of an ECU...

[Ruffryder]

"bobbobobbo" post=808227 wrote:


Yet then again... I'm not sure how Bayliner/Merc can ask for $4k more for the 250 engine if it's really just the difference of an ECU...

That is how Mercury makes their money...

4 stroke 75, 90, 115

357 285HP, 320HP

4.5 200HP, 250HP list goes on...

I would expect 20 HP gain.

http://www.baylinerownersclub.org/in...er-4-5l#805354

[Download_Complete]

That's one way they make profit on a product with razor thin margins.

Personally, I would just order the 250. It's a minimal uptick, it makes the boat go like stink, and it's an all-around great engine. The only way to improve on it is to add a Bravo drive, which Bayliner can't really do.

It will also be a key differentiation when you go to sell it....unlike having a 200 that you modified to a 250.

[Redwngr]

I emailed merc and asked if there was an upgrade package available (the 250 wasn't available when I bought my VR5) and the response was -- no. :angry:

the 200 is fine, but I would be more than happy to pay to upgrade to 250.

[Download_Complete]

You're in a different scenario - you already HAVE the 200.

Merc is not going to tell you "sure, just flash the ECU and you have the 250!" because then everyone would buy the 200.

You need to talk to a tuner who has done this work, and honestly, the engine may still be too new - i.e., someone needs to spend a crap load of money to buy a boat with one, and may not be willing to tinker with it and possibly blow it up.

[Norton_Rider]

Here's a company that makes a piggyback type tuner for the 4.5: http://www.magnumtuning.com/en/detai...er/4-5l-200-hp. My concern is that they make a lot of claims but show a generic dyno chart, instead of a dyno chart specific to the 4.5L engine.

[Ruffryder]

"Redwngr" post=808321 wrote:
I emailed merc and asked if there was an upgrade package available (the 250 wasn't available when I bought my VR5) and the response was -- no. :angry:

the 200 is fine, but I would be more than happy to pay to upgrade to 250.

inch: Of course they are gonna tell you NO

[Redwngr]

"Download_Complete" post=808365 wrote:
You're in a different scenario - you already HAVE the 200.

Merc is not going to tell you "sure, just flash the ECU and you have the 250!" because then everyone would buy the 200.

You need to talk to a tuner who has done this work, and honestly, the engine may still be too new - i.e., someone needs to spend a crap load of money to buy a boat with one, and may not be willing to tinker with it and possibly blow it up.

If they would sell an upgrade kit and it would still be supported by their warranty I would be more than happy to pay the difference in the original costs, plus a reasonable percentage.

[Redwngr]

"Ruffryder" post=808399 wrote:

"Redwngr" post=808321 wrote:
I emailed merc and asked if there was an upgrade package available (the 250 wasn't available when I bought my VR5) and the response was -- no. :angry:

the 200 is fine, but I would be more than happy to pay to upgrade to 250.

inch: Of course they are gonna tell you NO

Why? They are in business to make money and I'm offering to make them some more. If they offer an upgrade, I would expect it to be more than the cost of the difference between the cost of the 200 and the 250. I certainly wouldn't expect buying a 200 plus the upgrade to be cheaper than buying the 250.

[bobbobobbo]

Here's the follow up from Magnum Tuning asking if it bumps from 200 to 250+. Figure if anyone knew, maybe it's them

"Hello, Your follow up is highly appreciated, Bob. No you can't expect 25% boost. Not only the ECU programming differs but heads, valve timing, ignition timing, etc. Just the common sense says these blocks have no other difference. Let me know if I may assist you further.

Thank you"

If that's even completely correct..? Sounds like the 250 has more than just the ECU to upgrade maybe

[Download_Complete]

Certainly sounds like it. You can change all that stuff cheaply during development, and not affect the "footprint" of the engine thus allowing it to be used in place of the 200.

I dabble in ECU tuning in my cars (Volkswagen) and I have had great tunes (APR) and pretty awful tunes (Wetterauer, at the time highly respected). The great tunes added performance and no issues. The bad one added some performance and a litany of other issues (the Check Engine Light was constantly going off and needed resetting.) My point is if you want to go down this road, do so with an established engine, an established tuning company, and one that has an established reputation.

The 4.5 is too new to fall into any of these categories, thus making you the guinea pig. I would not want to be in that situation with a $35,000 boat and a warranty.

[Mike94ZLT1]

Sorry to bump such an old thread.

I dug through their parts catalog tonight and can't find a difference in part numbers. The block is the same. The heads are the same. The cam is the same. The intake and TB are the same. The springs are the same. The rockers and lifters are the same. The injectors are the same. All the major mechanical parts are the same.

The only difference I saw anywhere was in the operating range. The 200 redlines (per MerCruiser's website) at 4400-4800 rpm and the 250 redlines at 4800-5200 rpm. I'm not sure why there is a 400 rpm variable, but it is irrelevant. I'm almost positive the difference lies in the PCM and the tuning. The 200 has the same rotating assembly and parts to support the additional RPM, the same injectors and pump to supply the additional fuel, and the same exhaust to exhale through.

I would bet anything a tune would get us our missing 50 HP.

[Jeffw]

Here's a thought... Buy the 250, life is short. If that's not enough, THEN tune it. Remember, a boat is NOT an investment, but a means to blow hard-earned money in the name of having fun!

[Mike94ZLT1]

Here's a thought... Buy the 250, life is short. If that's not enough, THEN tune it. Remember, a boat is NOT an investment, but a means to blow hard-earned money in the name of having fun!

Thank you for your helpful input!

[jamesdgreen2016]

Just bought a Bayliner VR5 with the v6 200HP 4.5l engine at the start of the season. When you open it and look at the engine it has "200" on it, not "250". It's a 2017 boat model. I'm running a 4 blade 19" prop that is sized properly for the scenario. Got past the 10 hour mark last week and tried going to WOT. Per the manual for the engine, which is a hybrid manual for both the 200 and 250HP versions of the engine, there is a rev limiter for my 200HP engine set at 4900 RPM. So it shouldn't be able to go above 4900 RPM. The 250HP version is supposed to have a rev limiter at 5200 RPM. Have a look at what RPM I am getting in the picture here (2 people on boat). Also note that last week I loaded the boat up with six adults and four children (and one of those adults tips the scales at about 260lbs so Im talking capacity boat load), and I had good pickup and was able to achieve 5000rpm at WOT and just shy of 40mph. Which is to say I shouldnt be getting those results under that load with a 200hp engine and shouldnt be getting above 4900RPM period with this engine. Does this mean the 200 and 250HP engines are the same and they just put the wrong settings in mine, or does it mean something else?