PeachParts Mercedes-Benz Forum - View Single Post

Hit Man X · #2 04-18-2007, 03:41 AM

Dan -

You need to narrow down really what you'd like and if the extra bits on the 560 you actually need/use (i.e. SLS, heated seats, etc) as they do cost a bit more to maintain even for the DIY. Some of the options on the 560s you can and do find on 420s if you shop around. Heck, my SDL has power recline and heated seats and my 420 has power recline too.

Performance between the M103 and even the M116 is going to be pretty different also. Loads more low speed torque and will pull very strong to the shift too... the M117 has more torque and horsepower than the M116. The 420 is probably the best between the three for power, economy, features, etc. Just a fine machine for the money.

Economy is going to be pretty similar between the three freeway. The M103 will do a bit better as the motor is smaller, but it will tach up pretty high due to the short gearing out back (mine is going to receive the 2.88:1 to drop it down to a more refined level). Figure 20-23 for the M103, 18-22 for the M116, 16-21 for the M117. OF COURSE this will depend on your right foot for passing, cruising, geographics, use of A/C, etc, etc, etc. City driving is always lower, I usually figure 3-6mpg difference from highway cruise.

I have not driven a 4.2L M119 W124, just ridden. Seemed very stable at all speeds and ran like a bat out of hell, I have driven an M103 powered one and it rides a bit better than the W126, as it should... the suspension system is newer. Handling is also slightly better as it's more of a four door sports car where the W126s are large cruisers. I've had no issues tossing the 126s around into corners, they do handle rather well...

No wiring harness issues I've come into contact with. I own a VERY early production W126 (number 7200) and a very late 1990 model... no problems on that aspect. HVAC is somewhat tricky on them (usually the head unit), but it's very easy to service. Vac pods go bad, they're easy to rebuild. You do not want R134A. Evap cores do go bad on occasion, my '90 has a bad one. It's a good weekend project, not an issue to me. SLS issues typically arise from infrequent or nonexistant SLS fluid changes or bad accumulators. Accumulators are not too expensive. The height valve does go bad at times, but again... this is rare.

My best advice - drive all three of what you are comparing to make YOUR decision. You'll know what best suits you after driving all. I'd hang onto the E420 as it's just a fantastic, all-around vehicle then pick up a LWB 560. The SLS is a VERY welcome feature for me and I don't mind the economy loss for extra power.

The 300SEL isn't too swift around town, but what do you expect with a small motor? It's a good freeway car for the cash. 560 does it all, but lacks in fuel economy somewhat. 420 is NEARLY as quick as the 560. You can also bolt on Euro dual manifolds for the 420 and the 560 to pick up quite a bit of top end HP.