V6 or Straight 6?

[MichaelSB]

I am hoping to buy a 1998 R129 SL320, I am choosing between 2 cars, one is an early 1998 with a straight 6 and the other late 1998 with V6, both very sim spec including pan hardtop.
What do you all think the pros and cons of each are ,
thanks

 

[pioneercollector]

Personally i really like the smoothness you get from a straight 6 engine...... but that is only my thoughts, i have owned around 9 V6 cars and probably around the same in straight 6 guise .....

 

[Bobby Dazzler]

A V6 can sound fantastic but it will be hushed in an SL of that vintage, so you might as well go for the straight six and enjoy it’s glorious refinement which suits the opulence of an SL from that era.

 

[ChrisHGTV]

I remember reading that inline 6's have much better primary balance (ive just looked it up and it seems they actually have perfect primary and secondary balance). So on balance (sorry!) i would go straight 6. They are also rare these days with more V6's due to packaging i guess.

 

[Bobby Dazzler]

I remember reading that inline 6's have much better primary balance (ive just looked it up and it seems they actually have perfect primary and secondary balance). So on balance (sorry!) i would go straight 6. They are also rare these days with more V6's due to packaging i guess.

Indeed it is, and the reason that V12s are so silky, they’re two I6s combined.

 

[Mactech]

Indeed it is, and the reason that V12s are so silky, they’re two I6s combined.

One of these is a Silky V12, the other is a fighter jet

 

[Mactech]

One of these is a Silky V12, the other is a fighter jet

The Silky V12 won the standing start one mile drag race, by the distance you see here. The speed of the car at this point was about 200mph, the fighter jet was doing almost double that

 

[BTB 500]

The Silky V12 won the standing start one mile drag race, by the distance you see here. The speed of the car at this point was about 200mph, the fighter jet was doing almost double that

To be strictly accurate the Jaguar at the top was a (1960s) ground-attack aircraft. A fighter of that era such as the Lightning would have been rather more of a challenge ... despite being an even older design that had more than twice as much thrust

 

[pioneercollector]

I was going to mention the Daimler Double Six i owned decades ago, That was definitely a silky smooth engine ( The name of the model speaks volumes 'Double Six' ) ........ The more i think about it the more i actually enjoyed the straight six configuration - Don't get me wrong, some of the best cars i have owned have been V6, and they were all about grunt, all of the cars that i really enjoyed were straight 6's ( Jags, Datsuns, Vauxhall Royale, Camaro, Ventora, blah blah) ..... Even my Triumph Stag ended up being a 2.5 straight Six ...... ( Bad V8, Triumph PI engine was available ..... in it went!! ) And to be honest it wasn't as quick, obviously, but it was smooooooth

 

[Mactech]

To be strictly accurate the Jaguar at the top was a (1960s) ground-attack aircraft. A fighter of that era such as the Lightning would have been rather more of a challenge ... despite being an even older design that had more than twice as much thrust

I bow to greater knowledge, but the Jaguar vs Jaguar battle was still a great event with a really close finish.
Given that nobody really set the rules, apart from standing start and first to the mile marker, we were really amused to find out just how much 'optimisation' had been done due to the competitive spirit, after the race was run.
On the car we had removed the oil coolers and reduced the rear wing beyond any point we would run on the circuit.
The RAF had removed all the weapons and fuelled the aircraft with just enough to preform a take off, inverted fight and land. (Their purpose for the flight)
We had a good laugh about the fact that both racers and the RAF don't like to lose
The aircraft pilot was really good. The pilot of the car was Martin Brundle.

 

[Doodle]

I am hoping to buy a 1998 R129 SL320, I am choosing between 2 cars, one is an early 1998 with a straight 6 and the other late 1998 with V6, both very sim spec including pan hardtop.
What do you all think the pros and cons of each are ,
thanks

I'd worry less about which specific engine, and take whichever is the better car overall - condition, history and provenance.

 

[Bobby Dazzler]

I bow to greater knowledge, but the Jaguar vs Jaguar battle was still a great event with a really close finish.
Given that nobody really set the rules, apart from standing start and first to the mile marker, we were really amused to find out just how much 'optimisation' had been done due to the competitive spirit, after the race was run.
On the car we had removed the oil coolers and reduced the rear wing beyond any point we would run on the circuit.
The RAF had removed all the weapons and fuelled the aircraft with just enough to preform a take off, inverted fight and land. (Their purpose for the flight)
We had a good laugh about the fact that both racers and the RAF don't like to lose
The aircraft pilot was really good. The pilot of the car was Martin Brundle.

Great story (as always) and imitated by Top Gear more recently.

 

[alabbasi]

The M104 straight six is a great engine but the last facelift of the R129 got some great updates to the climate control system (from the push button to the LCD) which may not apply to your car if it does not have automatic climate control. They also got bigger brakes and if you're getting an automatic, it will will be mated to a 722.6 automatic which is far more robust when compared to the 722.5 which is a 4 speed with an external overdrive.

If you can find an M104 with a manual, it will be a delight to drive.

 

[BTB 500]

Great story (as always) and imitated by Top Gear more recently.

I remember seeing a few aircraft vs car drag races over the years ... IIRC TG have staged more than one?

 

[Mactech]

I remember seeing a few aircraft vs car drag races over the years ... IIRC TG have staged more than one?

Yes, we certainly weren't the first or last, but this was done with the 1990 Le Mans winning Jag shortly after the race that year.
I remember the day more as I was flown down to the venue from Kidlington by Martin in his helicopter. He is a really good pilot.
But, because I didn't drive there, I can't remember if it was RAF Abingdon or Benson, you don't see the signs at the entrance from 3000 feet!

 

[grober]

Mercedes-Benz M112 engine - Wikipedia

Note the M112 is an aluminium block engine rather than the M104 Iron block which may influence the weight distribution/handling a bit altho the R129 is a heavy car at the best of times--drive both types to see which suits you best?

 

[Dryce]

The RAF had removed all the weapons and fuelled the aircraft with just enough to preform a take off, inverted fight and land. (Their purpose for the flight)

On that basis it probably wouldn't have been so far behind the Lightning with the afterburners lit up.

The Lightning did what it did very noisily but also with relatively low amount of fuel and stores and only for a short period of time before it ran out of fuel. The Jaguar would carry a much higher relative amount of fuel and stores and for a much longer period of time. The Jaguar is often (unfairly IMO) overlooked as if it was low performance and the ground role maybe less interesting to the public - it was eclipsed by the likes of the Phantom, Harrier, and Tornado. At close to empty weight the Jaguar would not have been slow.

As an aside - the Harrier - had impressive acceleration without afterburning - this often gets overlooked because of the public focus on its vertical take off and landing capabilities - rather than it's short take off capabilities.

But then using the one of these two types wouldn't have had the same cachet as 'Jaguar vs Jaguar'.

With regard to the OP's question about straight vs V6. I always regarded the MB V6 as being decently smooth. The balancer shaft works. Is the OP looking at an automatic - if so does the straight 6v come with the 722.6 5 speed box - because if not I think the more modern transmission would be a more significant factor.

 

[DrNick]

View attachment 140984
The Silky V12 won the standing start one mile drag race, by the distance you see here. The speed of the car at this point was about 200mph, the fighter jet was doing almost double that

Nice picture. In terms of bragging rights, does the Jag (car) have a posted 0-1000 time? The flying one does (just!)

 

[BTB 500]

Nice picture. In terms of bragging rights, does the Jag (car) have a posted 0-1000 time? The flying one does (just!)

Not at ground level though!

 

[Mactech]

Nice picture. In terms of bragging rights, does the Jag (car) have a posted 0-1000 time? The flying one does (just!)

Really no idea! We were only really interested in lap times, but somewhere between a dragster and a XJ220. 700bhp in 900kgs, delivered in a silky smooth manner