R129 - V6 versus Straight

[Mercky]

Hi,
Considering buying a R129 SL and wondering what the consensus on the two engine types is, would seem logical to buy a post 98 V6 car but the earlier models, say 96, are cheaper but are they better value and which is the better engine in terms of performance/reliability/economy? Currently driving a 124 320 coupe sportline.
Thanks
Mercky

 

[television]

The face lift interior was around 06 1996, they are nicer inside in my veiw with better seats,08 1998 was the start of the V6, larger wheels,oval wing mirrors. Its a hard question over the engine, some prefer the straight 6, others the V6. Many extras became standard in 08 1998 including Rain sensor,dimming mirrors,folding mirrors. Xenon was an option.


Just to add the the 96 car will be a 129063 and the newer V6 and 772.6 box is the 129064
malcolm

 

[daveenty]

Had a straight 6 in my W210 E Class. Nice and torquey, but when I changed it to the W208 CLK with a V I was amazed at the difference. More responsive, better revving and (possibly, though unsure because of the difference in cars) more power. These were both 320 petrols.

A personal opinion (as always) but I'd try to get the V6, bring a smile to your face

 

[type49]

Both engines are generally very good but if you want the 5 speed electronic box, they came out mid 97. Previous to this, most would be 4 speed, unless you get a rare-ish but good 722-5 box. If you have seen a car you like, check out its spec on the russian link in these forums.

 

[Iain the gadget]

Deffo more economy with the straight 6!

 

[jberks]

Deffo more economy with the straight 6!

How?
Both 6 cylinder, both same cc but the V6 will have the benefit of the newer technology on the injection side plus the advantage in performance and economy of the 5 speed box. Hence I'd expect the v6 to be more economical than a straight 6, not because of layout, but just because of progress. Engines are constantly being improved so as a general rule, always go for the latest you can.Models and bodyshells however are a different matter.

 

[stargazerplus]

I have a V6 320 R129 SL. When buying I had a choice of two, one straight 6 in the other V. What has been said above is pretty much correct except that there will be barely any difference in economy. The V6 engine is an extremely toughly built engine and has some formula 1 features engineered in. Where it falls down is that it is a 3 valve design and not a 4 valve like the 320. The other problem is that it is a 90 degree V which means that it is not inherently balanced. Mercedes did this to manufacture it on the same line as the V8 which IS perfectly balanced. To counter this there is a balancer on the V6 to dampen out vibration. Mind you, having owned cars (previously a 320ce) with both engines, you would be hard pressed to notice a difference in smoothness.

What swings it for me is reliability:

I6

Head gasket problems £800
Biodegradable wiring loom £500

V6

Mass airflow sensor £50
Crankshaft position sensor £60
Crankshaft balancer pulley £100

(Oh but if the twin cats go on the exhaust reckon £1500, I'm sure the i6 would be expensive too!)

Doug

 

[Mercky]

Thanks everyone for all your replies, as it turns out I think I'll hang on to my coupe for a bit longer, hard to justify spending another €20K for an SL!

 

[big x]

Both engines are generally very good but if you want the 5 speed electronic box, they came out mid 97. Previous to this, most would be 4 speed, unless you get a rare-ish but good 722-5 box. If you have seen a car you like, check out its spec on the russian link in these forums.

Worth remembering The 5 speed electronic 722.6 came out in Sept 96 IE. 97 model year on the W202 and W210.Funnily enough I think these early boxes are more reliable than the later tiptronic ones but less reliable than the last of the hydraulic ones.

adam