Topic: Mercedes B-Class

[Traum]

I noticed that the B-class has a 2-valve engine (in both the B200 and the B200T). Isn't that a little ancient? Makes me wonder what kind of real world fuel economy it would have.

-Rick

[GTI-Gabe]

Real Fuel economy numbers are already posted on the MB website...

2L Model
- Acceleration,
  0–100 km/h 10.1 seconds, with manual transmission.
- Fuel economy,
     city estimate Manual: 9.2 litres/100 km
                       Automatic: 9.2 litres/100 km
- Fuel economy,
    highway estimate Manual: 6.7 litres/100 km
                            Automatic: 7.2 litres/100 km

Turbo Model
- Acceleration,
     0–100 km/h 7.6 seconds, with manual transmission.
- Fuel economy,
     city estimate Manual: 10.2 litres/100 km
                      Automatic: 9.5 litres/100 km
- Fuel economy,
    highway estimate Manual: 6.9 litres/100 km
                            Automatic: 7.4 litres/100 km

Plus, there's nothing wrong with having only 2 valves per cylinder since it produces better Torque... just look at the B-Class numbers.  The 2L produces 134hp and 136 lb-ft of torque!!!

[Shnak]

Plus, there's nothing wrong with having only 2 valves per cylinder since it produces better Torque... just look at the B-Class numbers.  The 2L produces 134hp and 136 lb-ft of torque!!!

I don't find that earth shattering... unless that torque is all available at 2000rpm, then it's pretty good for such a small engine. But we've seen better torque output from japanese small 4 cylinder engines, although probably at higher rpm...

[Traum]

Plus, there's nothing wrong with having only 2 valves per cylinder since it produces better Torque... just look at the B-Class numbers.  The 2L produces 134hp and 136 lb-ft of torque!!!

I don't find that earth shattering... unless that torque is all available at 2000rpm, then it's pretty good for such a small engine. But we've seen better torque output from japanese small 4 cylinder engines, although probably at higher rpm...

Yes, I was about to say the very same thing. The numbers are good, but not out-of-this-world. For the record, the Dodge Neon has similar engine output when it was released 10 years ago (although that engine was rather unrefined). Also, the Acura RSX has better performance and fuel economy than the Mercedes unit. VW/Audi's 2.0T is also a little stronger than the Mercedes unit.

-Rick

[sirAQUAMAN64]

Unless the B200T required premium, who wouldn't spend the dough to step up?

[Traum]

I think it is pretty safe to assume that the B200T will require premium fuel. The real question is whether Mercedes recommends high octane fuel for the base engine.

-Rick

[Shnak]

I think it is pretty safe to assume that the B200T will require premium fuel. The real question is whether Mercedes recommends high octane fuel for the base engine.

-Rick

That's very likely! As far as I know, all of their current engines require premium fuel. My girlfriend's parents' 1998 C230 does... and it's only a 2.3L that develops 148hp...

[johngenx]

Mercedes hasn't sold a car, with any engine, in our land for some time that doesn't call for premium gas.  If they follow "tradition" all B-Class models will specify premium gas.  Of course, if they were brave enough to sell us a B270D, we could have the super-duper torquey and well made 2.7L turbo diesel.  Make mine a B270 for $31K?  Maybe a B270 4-matic for $33,900?  At least then I wouldn't be saddled with FWD (Yuck) and would get outstanding economy.

Though, the Mazda 5 at $25K with every option (save for the gimmicky stand-alone options) looks like a super-buy compared to the B-Class...

[gabl]

I think the Mazda 5 is less usable than the B Class, as the last row of seats in the Mazda 5 is basically "dog seats" like. So it only left with 4 usable seats in the car. Whereas in B Class, all 5 seats have good leg rooms. Plus the seats are much more comfortable in B Class.

I wonder who would really buy the Mazda 5? I think the Mazda 3 Sport does the job good enough. The Mazda 3 Sports has more cargo room than the Mazda 5 from my observation.

[sirAQUAMAN64]

I disagree. The Mazda5 is EXTREMELY useable. All 3 rows are surprisingly roomy, although I wish it had the +1 middle row seat. I found the rear seat in the B rather flat, although it does sit nice and high. If the 2nd row in the Mazda5 had armrests on both sides, it'd win hands down for me.

So, yeah... who wouldn't jump to the B200T? I guess maybe that city-goer.

[Shnak]

I disagree. The Mazda5 is EXTREMELY useable. All 3 rows are surprisingly roomy, although I wish it had the +1 middle row seat. I found the rear seat in the B rather flat, although it does sit nice and high. If the 2nd row in the Mazda5 had armrests on both sides, it'd win hands down for me.

So, yeah... who wouldn't jump to the B200T? I guess maybe that city-goer.

I'm sure Mazda will lose a lot of sales just because of the seat disposition in the Mazda5. People want more than 4 seats AND have some cargo space... you can't have both with the Mazda5... it's either 6 passengers OR cargo space. So in reality, the Mazda5 is a taller Mazda3, but certainly no MPV-alternative.

[sirAQUAMAN64]

Yeah, but how often do you actually see 7 people in minivans? It's usually single, and older elderly couple, 3, 4, or 5. Sometimes 6 for a trip to airport or visiting family. Rarely are 7 crammed in there. Although admittedly, with 6 there's a restriction on cargo volume, but again usually luggage is reserved for trips. The 5 has superb flexibility. 

I wish it had 6+1, but it doesn't. No biggie to me, but for a family of 5 it might be, you're right. Less families are having 3+ kids nowadays tho.

I just spoke to a lady today who was filling up her base Mazda5 as I was checking my tire pressure - I still had 600+ km's to go on my tank    Anyhow, she said she used to have a minivan, but it was just too much. And she just got out of an Aerio to get the Mazda5 - she said she uses it to shuttle her kids around and that she travels a lot and it's great on gas - just as good as the Aerio (which I realize is no Civic either, but...), that it was a great price, and that she liked the looks of it. I kept asking Q's and she said it was a great deal, and is much larger than a Matrix which was too small for her. Hers looked exceptional in white with tint too    She 'loves it'.

To me, that's the buyer. It makes loads of sense to me. A Mazda3 Sport just doesn't have the interior volume - nowhere near it, even just in spacious airyness similar to a van or CR-V. It's not as family oriented as the 5. And the 5 even costs about the same! Not doubting buyers may look at both though becuase they're essentially very similar and marketed as 'zoom-zoom' at similar cost.

Have you seen the 5 up close and sat in it yet Shnak?

[s60]

I was in getting thre ZX5 15,000k (already) serivce done, and was speaking with a salesperson. He mention
he has lost quite a few Freestar sales to the Mazda5.

[a4_tom]

Many European carmakers like Peugeot and Citroen, still uses 2-valve-per-cylinder engines due to their low-end torque.

[johngenx]

I don't care if it's got 2 valves or 5.  I want a flexible driveline that is easy on gas and feels right.  For a Honda S2000, the low-end grunty feel of a "low tech" engine won't cut it.  Give me the multi-valve rev-happy screamer!  If MB can get good economy and feel out of a 2-valve design, more power to them.  That will help at the 400-500K mark when I'm looking at a top end job.  Less valves is less cost...

Also, less valves don't mean higher torque unto themselves.  The larger valves required can't rev as high thanks to valve weight, meaning that we have to engineer a cam profile that maximizes low end power.  Also, one large intake valve has a different cylinder fill profile than 2 or 3 intakes that works better with a flatter cam profile.

[GTI-Gabe]

For the record, the Dodge Neon has similar engine output when it was released 10 years ago (although that engine was rather unrefined).  Also, the Acura RSX has better performance and fuel economy than the Mercedes unit. VW/Audi's 2.0T is also a little stronger than the Mercedes unit.

-Rick

Taken from their perspective websites...
RSX 139 lb-ft @ 4000 rpm
RSX Type S 140 lb-ft @ 7000
Neon SX 130 lb-ft @ 4600
MB does 136 lb-ft @ 3500

The MB also has 11:1 compression, so I'm sure it requires premium

and who cares how "powerful" and "efficient" the engine is.  My 94 2L GTI produces 115hp and it's a hoot to drive @ 1100 kgs    (the B-Class weighs in @ 1270 kgs)

[johngenx]

The MB also has 11:1 compression, so I'm sure it requires premium

The compression ratio is not a direct indicator of the fuel requirement.  Honda builds many high compression engines that do not require premium gasoline.  It depends on valve layout and timing, cam profiles, ignition timing, plug placement, combustion chamber shape, squish area and bore/stroke relationship.

The fuel requirements depend on how long you want the fuel to delay it's burn.  Higher octane gas requires a higher pressure to ignite.  Contrary to popular belief, higher octane gas is not "more powerful."  Now, many high compression engines are built for performance and have steep cams, small squish zones and large amounts of valve overlap.  These factors often mean that they require high octane gas...

[Traum]

Taken from their perspective websites...
RSX 139 lb-ft @ 4000 rpm
RSX Type S 140 lb-ft @ 7000
Neon SX 130 lb-ft @ 4600
MB does 136 lb-ft @ 3500

Let's not get into the hp vs torque debate, eh?

-Rick

[Shnak]

Taken from their perspective websites...
RSX 139 lb-ft @ 4000 rpm
RSX Type S 140 lb-ft @ 7000
Neon SX 130 lb-ft @ 4600
MB does 136 lb-ft @ 3500

See that's excellent. That's a good amount of torque available relatively quickly! I'm sure the base 2L engine in the B-Class will be more than enough for most needs. It won't be a sprinter, and highway passing will be hazardous when loaded with a few people, but for most tasks, it will be perfect. And probably more reliable than the turboed version too.

[Shnak]

Have you seen the 5 up close and sat in it yet Shnak?

No I haven't had a chance yet... I will do that soon enough. I don't remember, can you fold down completely the 3rd row seats? Or remove them completely? I really have to go check it out for myself... That and the Tribeca... It 'intrigues' me...