bmw i8 power

[renagade]

Hi Guy's
Just reading about the twin motor bmw i8 that has a three cylinder 1500cc engine in the back that has over 200bhp to offer , why has my 1600 cc e-hdi only give me 110 bhp ???

[Paul-R]

Is it a petrol engine? They spin themselves faster to give high BHP at the expense of the low range torque that actually makes for relaxed driving. You may even find that at 2000rpm your engine gives out more torque than the Beemer engine.

[Zelandeth]

I might be wrong, but I thought the drive in the i8 was all electric, and the petrol engine was used as a generator...or have I made that up?

[NewcastleFalcon]

I was listening to Jodie Kidd appearing on Graham Norton's radio 2 show yesterday and when asked about electric cars said....

I've got a hybrid, so I also have a great big kind of massive-engined car as well just to kind of fuel my need for speed so I thought it would be really good to get a balance, so I've got a BMW I8, very pretty, a *very tronny looking car. That's a hybrid and its fantastic........every time I drive into London I use the hybrid...

* no idea what that means!

Wow she must have a real need for speed if a BMW I8 can't supply it!

"Boasting a turbocharged three-cylinder engine, which accelerates from 0 to 62mph in just 4.4 seconds,"

Amongt other things She's a pub landlady in Sussex now! The Half Moon at Kirdford to be precise.

[daviemck2006]

I might be wrong but BMWs are horrible and driven by (-expletive removed-)

[Paul-R]

If it's a hybrid can't they use the i.c. engine in conjunction with the electric motor for an extra burst of power? Perhaps that's where the "200 bhp" figure comes from?

Even if not, turbocharging a petrol engine will give a boost in power compared to a n.a. engine - just as turbocharging a diesel engine. The rule of thumb remains the same - the petrol engine will spin higher to get the extra power compared to a diesel though.

By-the-by, the 1600 engine in our 308 reputedly pushes out 120bhp. The auto version of the same engine is more powerful putting out, I think 150bhp. And if that's not enough, I've read that the 1.6 is now being replaced by a 1.5 which gives the same 120bhp. I don't know if there's an auto version with higher power though.

[andy5]

I might be wrong, but I thought the drive in the i8 was all electric, and the petrol engine was used as a generator...or have I made that up?

I don't know, but bear in mind that at 60 or 70 mph a modern car needs only 25 to 40 bhp to maintain speed.

For all the concentration on maximum output, and acceleration figures, the proportion of time the car spends operating like that, accelerating hard, or flat out speed, is only a couple of per cent.

So an ideal hybrid car might have a very large energy store (battery or flywheel) for acceleration and braking, and just a steady state input from a small engine as a generator, modestly supplying the average needed across a whole trip.

Clearly cars don't actually work that way yet, and perhaps never will, if the required store size is too big. Instead many of them seem to be at the top of the market, and overpowered for most use.

Consider someone owning one of these, planning a trip which starts at the bottom of a hilly area, which they like to hurtle up. Maybe on the flat and driven cautiously the electric range will be 30 or 40 miles, but giving it real welly uphill they can reduce this to 6 or 8. Then downhill a bit, and it starts to recharge. But then another uphill, and suddenly you need the engine on its own.

No, instead of all that, as in a post above, just use it to trickle into London for a bit of posing.

[bobins]

I was listening to Jodie Kidd appearing on Graham Norton's radio 2 show........

Amongst other things She's a pub landlady in Sussex now! The Half Moon at Kirdford to be precise.

The pub's not a million miles away from me.... but I don't think it caters for the likes of me
From the menu:
"Ribeye steak, béarnaise sauce, hand cut skin on chips £24.00
Braised lamb shepherd’s pie, buttered seasonal greens £14.50
Roast cod, smoked mushy pea puree, scraps, tartare dressing, malt vinegar gel & fries £15.50"

...smoked mushy pea puree.... malt vinegar gel.... WTF !

I think I'll stick to my home made cheese on toast