performance difference??

[parker]

could any one tell me is there much of a performance difference between the 4.2 and the 4.5 cerb's. would like an idea so that i don't waste a prospective sellers time if there is. thanks

[BCA]

Generally 4.5s have better low down torque/ a flatter torque curve. BHP wise there is nothing in it (some 4.2s have been known to have more horses underneath the bonnet infact) The 4.2 will feel more "raw" and have most of the power higher up in the rev range. The 4.5's are said to be more driveable generally because of the low down torque, dont think there is that much in it though.

To be perfectly honest there usually is more difference between two cars of the same engine size than 4.2/4.5. Try a few and pick a good one, if you pay more for a 4.5 you are only doing so for the wheels/ brakes and resale IMHO. (we bought ours for 4.2 money)

The only real advantage the 4.5 has is if you want more power in the long term with a full Red Rose conversion, which ups torque and power all round. For 4k its not too unreasonable but you will probably find better gains through decent suspension/ brake packages that any good independant should be able to provide.

4.5 - better at lower rpm, no power advantage otherwise, more upgradeable via the factory, bigger wheels and better brakes.

4.2 - same power, more raw (can be a good thing), so much cheaper that wheels/suspension mods can be done to bring it to 4.5 money!! (With all work done it should be a fair bit quicker round track than a standard 4.5 then)

Infact, there are so many cars just running 18" spiders that you can even factor out the wheels with most cars. Try a few cerberas and buy the one that feels right, looks right and is in tip top condition.

[j_s_g]

BCA said:

Lots of good stuff

Not sure that extra low down torque makes a car more driveable, really. Definitely agree that unless you're going to get a RR, the price difference could easily be spent on upgraded suspension, etc. on a 4.2 to make it a much faster & more predictable car than a 4.5. Best just to set a budget for the car, one for maintenance, and find the car that you like the best for the price, whatever engine it has (S6 included).

[kojak69]

You may find that the 4.5 can vary quite a lot from car to car, on the 420 bhp stated. A lot can be knowhere near the 420bhp. The 4.2's are generally nearer the 360 bhp quoted, and are more consistant. You may also find that some 4.2's seem quicker than the 4.5's due to what i've mentioned.

Tend to agree with j_s_g, and spend the extra money on upgrades for a 4.2.

[shpub]

Upto 100 ish there is little difference or put another way , the difference will often be a perceived feeling due to variations in power delivery. The good 4.2s tend to be a bit cammy going from poodle mode to Oh my God in a matter of a few hundred revs. The 4.5s are a bit smoother.

Over 100 the 4.5 will usually start to pull away.

[jamster]

not interested in the speed six Parker? You'll not notice the difference on the queens highways anyway. More comfortable refined ride as well. If your thinking about the track days then the larger engine is probably the best bet although the speed six will still toast all the ferraris, scoobys and evo's around anyway.

Dare i say, more reliable as well.......