[mowflow]

With the engine idling or driving around town it won't be but on the motorway it will be. The 116i will be revving much higher at motorway speeds so will be louder. At around 60 on dual cabbage ways most diesels are just ticking over.

[ovekvam]

Originally Posted by mowflow

With the engine idling or driving around town it won't be but on the motorway it will be. The 116i will be revving much higher at motorway speeds so will be louder. At around 60 on dual cabbage ways most diesels are just ticking over.

It is the other way around. The 116d has a 3.08:1 differential ratio, while the 116i has 2.81:1. Both cars will easily use the top gear at motorway speeds, but the petrol version has even lower RPM than the diesel.

[mowflow]

I'm not smart enough to translate those figures. I can only compare the 2 closest models I have driven, 116i and 118d. The 118d definitely sat at lower revs and was quieter while in 6th on the motorway between 65-70mph.

[ovekvam]

The 118d has a 2.65:1 differential ratio, so it has 5 percent lower RPM than the 116i, driving at the same same speed in the same gear. The 116d has higher RPM than the 116i.

The petrol engines are running slightly smoother, though. The diesel engines have more vibrations and rattle, particularly at low RPM.

[HighlandPete]

Originally Posted by ovekvam

It is the other way around. The 116d has a 3.08:1 differential ratio, while the 116i has 2.81:1. Both cars will easily use the top gear at motorway speeds, but the petrol version has even lower RPM than the diesel.

Don't forget to add in the the gearbox ratios. Diesel gearbox has a longer overdrive ratio in 6th, making the overall gearing longer than the 116i.

From the data I have, the standard 116d is 0.645 in 6th, 116i is 0.830 in 6th, making the overall ratios in favour of the diesel. (1.98 for the d vs. 2.33 for the i).

HighlandPete

[ovekvam]

Originally Posted by HighlandPete

Don't forget to add in the the gearbox ratios. Diesel gearbox has a longer overdrive ratio in 6th, making the overall gearing longer than the 116i.

From the data I have, the standard 116d is 0.645 in 6th, 116i is 0.830 in 6th, making the overall ratios in favour of the diesel. (1.98 for the d vs. 2.33 for the i).

HighlandPete

Good point! :-)

I thought they had the same gearbox, but didn't check facts. But I have to say the 116i has surprisingly tall gears. You can reach top speed in fourth.

[JonF1982]

Don't have any science to back it up, but the salesman said you might notice the car is quieter, which it did seem to be in all situations on the demo.

but I've been wrong before, and I will be again...

[logiclee]

At 70mph our 116i is at lower rpm than my 2.0Tdi Passat.

35mph/1000rpm V's 33mph/1000rpm.

Both are Auto though.

Cheers
Lee

[logiclee]

Originally Posted by ovekvam

Good point! :-)

I thought they had the same gearbox, but didn't check facts. But I have to say the 116i has surprisingly tall gears. You can reach top speed in fourth.

For manual gearbox ratios.

4th in the 116d is 1:1 and that's the same as 5th in the 116i

5th in the 116d is taller than 6th in the 116i. 0.781:1 V's 0.83:1.

6th in the 116d is 0.645:1

Have to do the maths with the final drive to see how it works out.

Cheers
Lee

[will-w]

I've got a 116i as a courtesy car while my 118d is in for work.

At idle the 116i is almost silent in comparison. The exhaust note is nicer on the ears and you can really hear the turbo spool when driving progressively.

At 70mph it runs at 2,200rpm, my 118d runs lower at 1,900rpm.

So far I've driven the car on just about every type of road there is from lovely smooth country roads to city traffic and motorway.

The 118d is better at:
Motorway travel; It's more refined and has more poke to maneuver between lanes
Country roads; it has more usable power, I find that you're constantly stirring the gearbox in the 116i to keep it in the power band.

The 116i is better at:
Town and City travel; the petrol engine is more responsive from standstill and is noticeably quieter.

I came home the same way that I've come in the 118d and the 116i was worse on fuel economy at an average of 39mpg over a 64 mile mixed trip. This compares to the 48mpg of the 118d.

The 116i was running an average of 34mpg until I hit traffic on a country A road and was forced to do a constant 50mph.

[ovekvam]

Originally Posted by will-w

The 118d is better at:
Motorway travel; It's more refined and has more poke to maneuver between lanes
Country roads; it has more usable power, I find that you're constantly stirring the gearbox in the 116i to keep it in the power band.

The power band is actually wider in the 116i, but you will perhaps not want to use the high RPM part of it, due to consumption issues. If you drive on a track with no thoughts about saving fuel, the 116i is very easy to keep within the power band, which is pretty much 4000-6500 RPM. The diesel engines have a narrower RPM range where they perform well, and require more gear shifting.

The advantage with diesel engine, is that the narrow power band is at rather low RPM, where the engine has low consumption. Even when pushing the car hard, it will not get very thirsty. This is why diesel cars can be competetive in endurance racing, running very long stints on the track, while petrol powered race cars need to stop for fuel.