[AlanHo]

I would appreciate help from one of our kind members who runs a 2010 or 2011 i30 diesel with a 6 speed manual box and a sat-nav which displays the car speed.

I would like to compare gear ratios with the new car. Why? - because my new car feels higher geared - but it may simply be an illusion because the engine is still tight.

What I would appreciate is someone to run their car at exactly 2000 rpm in each gear and note down the car's exact speed as shown on the sat-nav - not on the car's speedo, which is not usually dead accurate.  I also need your tyre size.


I will then produce a table comparing both models.

My car - 2012 Style 1.6 CRDi 128PS
Tyres 205 55 R16

Speeds at 2000 rpm in km/hr  18  32  56  79  93  111
Sppeds at 2000 rpm in mph    11  20  35  49  58   69

PS
If others with different car specs wish to participate - that would be a bonus. I could then produce a table showing the car speed per 1000 rpm for each model that is submitted. It all adds to our i30 data base.

[Dazzler]

Good idea Alan.. The first candidate that comes to mind would be Lakes (John) he fits your description..

 If no one else responds or John doesn't see this it might be worth a PM (John usually only come on very early our time - before he goes to work) 

[AlanHo]

BUMP

Come on guys - one of you must have a 6 speed manual diesel and a sat-nav........

[rustynutz]

'Twas thinking about this yesterday as I was driving but I didn't have a pen and paper handy, and of course I only have a 5 speed. 

[Doggie 1]

 

[rustynutz]

Well, I went for another drive and here's what I came up with: 

1st - 15kph
2nd - 28kph
3rd - 48kph
4th - 67kph
5th - 85kph

[AlanHo]

Thanks Russ - you are a kind gent. Now to find someone with a 6 speeder.............

[Doggie 1]

Mine's a diesel 5 speed and my readings as per my SatNav were:

1st:   15 km/h
2nd:  29 km/h
3rd:   49 km/h
4th:   68 km/h
5th:   88 km/h

Dave 

[Dazzler]

I'll PM lakes with a link to this thread .. this is right up his alley

Can anyone else think of a 6 speed owner who uses a GPS and is a regular visitor (Is so please PM them a link)

[Doggie 1]

Alan, I can't find it now, but did you get my results that I posted with my 5 speed?
I know you want 6 speed results but thought I'd at least give you those.

[AlanHo]

Alan, I can't find it now, but did you get my results that I posted with my 5 speed?
I know you want 6 speed results but thought I'd at least give you those.

Sorry Dave - I cannot see it in the thread - did you post it elsewhere?

[Doggie 1]

I thought (I'm sure  ) I posted it in your original request thread.

Maybe the gremlins are at work again. Didn't someone else post the results for a five speed too? 

Anyhow, I'll post it again. These are at 2000 rpm, speeds from SatNav.

1st:     15 km/h
2md:   29 km/h
3rd:    49 km/h
4th:    68 km/h
5th:    88 km/h.

[rustynutz]

'Twas me that posted the other one, Dave and I'm buggered if I can find them now.... 

[Doggie 1]

Spooky 

[AlanHo]

Not guilty m'lord.

Dave - is your car a 1.6 or 2.0 litre?

[rustynutz]

Lucky I still have the piece of paper I wrote them on.....

1st - 15kph
2nd - 28kph
3rd - 48kph
4th - 67kph
5th - 85kph

I might check fifth again as I did this on a hilly back road......
Edit: just checked and all's good....

205/55/16 Tyres.

[AlanHo]

Thanks guys.

Could be useful to include wheel/tyre size.

[rustynutz]

Seems like the Gremlins are back....I wonder what other posts have gone walkabout? 

[rustynutz]

Could be useful to include wheel/tyre size.

Good thinkin', 99.....

[Doggie 1]

Not guilty m'lord.

Dave - is your car a 1.6 or 2.0 litre?

1.6 diesel.

[asathorny]

Alan, I am unable to help you on this research BUT, and I have to say before I make a fool of myself here that I fully expect to be shot down in flames, BUT,  since the speedo is less than reliable (mine is bout 3 MPH fast) what makes you think that the rev counter is any better ????

Not that I want to throw a damper on your excellent research, from which we all benefit me included.

Just a thought for you to factor in or disregard as is your wont.

Kind regards
Asa

[Shambles]

Seems like the Gremlins are back....I wonder what other posts have gone walkabout? 

None, hopefully. I "invisibilised" the 5-speed posts as they seemed irrelevant to what Alan was desperately asking for. Ah well, they're "uninvisibilised" now 

[rustynutz]

Seems like the Gremlins are back....I wonder what other posts have gone walkabout? 

None, hopefully. I "invisibilised" the 5-speed posts as they seemed irrelevant to what Alan was desperately asking for. Ah well, they're "uninvisibilised" now 

So you didn't read this part of Alan's original post then, Steve.....   

If others with different car specs wish to participate - that would be a bonus. I could then produce a table showing the car speed per 1000 rpm for each model that is submitted. It all adds to our i30 data base.

Me thinks you can go stand in the naughty corner now... 

[Shambles]

So you didn't read this part of Alan's original post then, Steve.....   

My mistake entirely 

Been spending far too much time on the new theme options 

[AlanHo]

Alan, I am unable to help you on this research BUT, and I have to say before I make a fool of myself here that I fully expect to be shot down in flames, BUT,  since the speedo is less than reliable (mine is bout 3 MPH fast) what makes you think that the rev counter is any better ????

Not that I want to throw a damper on your excellent research, from which we all benefit me included.

Just a thought for you to factor in or disregard as is your wont.

Kind regards
Asa

ASA  - it had not escaped my thoughts ( great minds thing alike) - but I guess the rev counter stands more chance of being accurate than the speedo which has got tyre rolling radius and slippage to contend with and a safety factor tweak built in by the manufacturer. I started the thread because my new car - though more powerful than the last - feels less lively in the higher gears and I wondered whether the gear ratios had been lifted in the interest of squeezing the lowest emissions out of the government tests. It might be because the engine is still tight - only time will tell.

[asathorny]

Yeppers Alan, I should have known you'd have factored it in <sigh>...   And yes it probably is a tad more reliable  ...

I'll just keep and eye out so you don't miss anything 

I quite fancy the new i30 but at the moment I am impecunious but it's on my bucket list 

[rustynutz]

Alan, for a while now I've been wondering why you just didn't compare the gear ratios that are listed in the specifications of the new and old i30's..... 

I've now found out why, I'm buggered if I can find any gear ratios listed for the new generation i30....

Are they shown in your manual? 

Anyhow, here are the Aussie model ratios, hope these will help with your comparison. 

                                                                1.6                                        2.0                                  1.6 CRDi

[AlanHo]

Russ

Thanks for that info - but you have discovered why I tried to find another way of comparing the gearing.

The only reference I found to the gear ratios for the new i30 6 spd diesel was in the UK Autocar magazine road test of 14th March 2012.
This was as follows :-

1. Ratio = 3.61   speed per 1000 rpm= 4.8 mph
2. Ratio = 1.95   speed per 1000 rpm= 8.9 mph
3. Ratio = 1.37   speed per 1000 rpm= 12.7 mph
4. Ratio = 1.03   speed per 1000 rpm= 16.8 mph
5. Ratio = 0.89   speed per 1000 rpm= 19.5 mph
6. Ratio = 0.77   speed per 1000 rpm= 22.5 mph
Final drive ratio = 4.267

However - I don't believe this data. For a start my car in 6th gear does 69 mph at 2000 rpm = 34.5 mph (55.54 km/h) at 1000 rpm. The autocar figure is only 22.5 mph.

Also Autocar list the maximum speed as 115 mph for 6th gear at 5112 rpm. This is equal to 22.5 mph at 1000 rpm

If I could get my car in 6th gear up to an engine speed of 5112 rpm I would be travelling at 176 mph.


If we start from scratch and use the tyre size data - the formula for calculating the car speed for a given engine rpm is :-

km/hour = (Engine rpm x Tyre Circumference in metres) divided by (Gear ratio x final drive ratio x 16.66)

The tyre circumference can be found here ...http://bndtechsource.ucoz.com/index/tire_data_calculator/0-20

Assuming your 6 speed 1.6 CRDi cars are using 205 55 R16 tyres - the circumference is 1.927 metres

Using the above formula : engine speed 2000 rpm, gear ratio 0.596, final drive 3.941, 6th gear -  works out at 98.50 km/hr. This is quite a bit higher than the 85 and 88 km/hr speeds found by you guys using your sat-navs with your 5 speed diesels.

I have a similar problem with my car. If the autocar 6th gear ratio figures are used the car speed at 2000 rpm should be 70.4 km/hr whereas my sat-nav test indicated a car speed of 111 km/hr

For a second test I found a web site in which you enter your tyre size and gear ratios and it does the calculation for you...
http://www.boosttown.com/gearbox_differential/speed_calculator.php

Hence I am confused - unless I am doing something stupid with my maths there is an anomoly with the gear ratios declared by Hyundai and the Autocar magazine when compared with the actual tests using a sat-nav.

[rustynutz]

Thanks for that, Alan...unfortunately most of it goes straight over my head so not much help here....

Oh, and I've just realised I didn't include which model was which in the gear ratio pic....

They are 1.6, 2.0 Petrol and 1.6 CRDi.......