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[Webby the Bear]

Hi guys,

DISCLAIMER: I know the 0-60 test has a lot of variables like imperceptible gradients, wind strength and direction, temperature, stopwatch/acceleration being synchronised spot on etc etc however I feel I'm getting close to what the manufacturers say and going to be honest I love doing this test when I'm bored

Anyway, 0-60 in my car should be 9.5s.

I did it the other day and got an awesome 9.3s.

However, did it two days ago and got 10.5s. However, there was me, the wife and 2 full size spare wheels in the boot (1 is my spare, the other was one I 'borrowed' from college to have the tyre off asit had 7mm and mine had...well... something worse  )

Dropped the wife off and went to do the test by myself (still with 2 full sized spares in the boot) managed bang on 10s)

So, to recap:
Me on my own with just 1 spare - 9.3
Me, wifey and two spare wheels - 10.5
Me, no wifey and two spare wheels - 10.0

Is this expected?

Also, I was chatting to my tutor the other day about EGR. I thought the exhaust gas going back in to the inlet (when EGR valve is opened) was actually more combustable. However he told me it's ''inert'' thus has no reaction to combustion. Therefore that exhaust gas going back in is essentially ''dead'' and there's going to be less power. I'm assuming there's no way of finding out when the EGR valve is activated but if it was open when I was doing my 0-60 test then that would also affect it???

Your thoughts to all the above?

[05omegav6]

Weight makes a difference... the handbook might tell you how the GM figure is reached, ie fuel load/number of people etc. A tank of fuel weighs about 67kgs for example. GM might calculate the performance/economy figures at maximum gross vehicle weight, but equally might be a 40kg test driver and about 3 litres of fuel and nowt else

[Webby the Bear]

I know test drivers are meant to be skinny but 40kg.... I'm surprised he'd have enough strength to open the doors 

Only kidding Al but I get the sentiment. Thinking about it I suppose without knowing exactly how those figures have been calculated (i.e. passengers in car, fuel load, tyre pressures, misc. weight etc) it's going to be impossible to compare real world times to manufacturers' times.

I suppose though that only a second over what they said with half a tank, two passengers and two full sized spares is pretty good? What do you think?

[05omegav6]

As a 0-56 time, not bad

[Webby the Bear]

Huh? lol that was to 60

[Webby the Bear]

Found this with soooo many variables too...

http://en.wikipedia.org/wiki/0_to_60_mph

[Webby the Bear]

Ps, anyone think I may beright on the EGR thing?

[Webby the Bear]

Just to add... I've read a thread on this very site where kick down is sometimes very powerful and some other times its just a gradual push (still drops a gear and red lines but power is sometimes applied faster and harder and other times not). The person who's thread it was blanked off EGR and had constant good/hard power from then on.

This would explain everything......

[martin42]

Go to santa pod when they do rwyb and you will get a 0-60 and also quarter of mile time.

[05omegav6]

Said it before and shall say it again...

What your speedo says and what the car is doing are two different numbers

[05omegav6]

Go to santa pod when they do rwyb and you will get a 0-60 and also quarter of mile time.

As long as Webby keeps his boot in

[Webby the Bear]

Said it before and shall say it again...

What your speedo says and what the car is doing are two different numbers

Is the speedo always wrong then?

[Webby the Bear]

Go to santa pod when they do rwyb and you will get a 0-60 and also quarter of mile time.

Would love to. But if I'm not comparing like for like (my set up vs GMs set up) then it's going to be pointless.

Al, you said that the handbook may say the 0-60 testing conditions? Which handbook exactly?

Does anyone havethis info? Then I can do a proper test 

Would also be interesting to hear some 0-60 times done by OOFers and how they set up i.e. no. of passengers, extra weight added, any weight removed (thinking seats for example) fuel load etc etc

[Webby the Bear]

Ps...

I've been putting it in 'D' and in sports mode. Should I perhaps do it in '2' andin sports mode?

[omega3000]

Ps...

I've been putting it in 'D' and in sports mode. Should I perhaps do it in '2' andin sports mode?

Aye you will notice the difference , mite need a change of pants if you floor it  Oh and keep an eye on the fuel gauge 

[Webby the Bear]

Ps...

I've been putting it in 'D' and in sports mode. Should I perhaps do it in '2' andin sports mode?

Aye you will notice the difference , mite need a change of pants if you floor it  Oh and keep an eye on the fuel gauge 

 

You reckon that will be faster?

[omega3000]

Ps...

I've been putting it in 'D' and in sports mode. Should I perhaps do it in '2' andin sports mode?

Aye you will notice the difference , mite need a change of pants if you floor it  Oh and keep an eye on the fuel gauge 

 

You reckon that will be faster?

Yep  Well it is in the 3.0 , never tried it in a 2.5 as never owned one 

[Webby the Bear]

Right, I'm off to try all this without the spares...... on my private track of course 

[omega3000]

Right, I'm off to try all this without the spares...... on my private track of course 

Yourve been gone too long now  Stop thrashing it 

[martin42]

He ran out of petrol lol

[omega3000]

He ran out of petrol lol

Maybe changing his pants 

[Webby the Bear]

In the end couldn't do it.... my private track was busy 

As I'm going to drive it in '2' and thenget it to 60 will it get to the red line and sit there until I get to 60? Don't really fancy staying ON the red line for long 

[omega3000]

In the end couldn't do it.... my private track was busy 

As I'm going to drive it in '2' and thenget it to 60 will it get to the red line and sit there until I get to 60? Don't really fancy staying ON the red line for long 

Dont forget the gearbox learns to the way you drive , at least it does when it works 

[Rods2]

There will be many variables when you do a 0-60mph time that will affect it slightly, like ambient air temperature, humidity, how warm engine, engine oil, gearbox and diff oil are. Tyre pressures and how hot you tyres are as this will marginally affect effective tyre diameter, all up weight etc., etc.

A way to eliminate all of these factors is Beachy Head, it is very good for a one off 0-120mph time.

[Webby the Bear]

Thanks Rods. So based on my initial post with my varied times you wouldn't be concerned that it doesn't do 9.5 bang on every timeand in fact gets slower some times?

[2woody]

EGR is part of a strategy to reduce NOX emissions ONLY and of no use for anything else. In the UK, MOT stations can't even measure NOX, so it remains part of the type approval of the vehicle when new.

inducing exhaust gas into combustion does affect the flame properties - basically it reduces peak combustion temperatures, which is where the NOX is formed. But it also reduces performance quite markedly.

EGR is used only when needed during the EC drive-cycle used for the type-approval test. Mainly during the cold-start part. Most of the EGR use during normal running is to keep the system working and not for an emissions purpose.

hope this helps

[Webby the Bear]

Thanks 2Woody, appreciate that.

On to the 0-60 results does it make sense about why the figures are different? Would you be concerned i had a performance issue (no pun) with those fluctuating times albeit max fluctuation being 1 second??

[Kevin Wood]

Thanks 2Woody, appreciate that.

On to the 0-60 results does it make sense about why the figures are different? Would you be concerned i had a performance issue (no pun) with those fluctuating times albeit max fluctuation being 1 second??

If you're measuring with a speedo and stopwatch I think any variation can be put down to the inaccuracy of the measurement method. I think you're doing well to get a spread of only a second, TBH.

[Webby the Bear]

Thanks Kev,

i shan't be concerned with it anymore