Engine Choice

wymondham

Hi All

I'm looking to buy a new car this summer and the model I'm looking at currently has two flavours of engine (Renault/Nissan brand), with two new ones out this spring. I drive mainly local with the occasional longer journey and with the heavy 'frowning' on diesels i'm tempted to steer clear of this. I've heard that smaller turbo engines can give problems, but the new ones are 1.3 and not 1.0 as seems to be the main culprits of these plus the new ones are more economical, so what would the crew recommend? (I think its too early to adopt electric as I park on the street).

Current Engines:

1.5 Blue dCi Diesel 115 BHP
1.6 Sce Petrol 115 BHP (naturally aspirated)

New Engines (well, same engine, different power):

1.3 Petrol Tse 130 BHP (Turbo)
1.3 Petrol Tse 150 BHP (Turbo)

Goudy

This is something only you can decide, though I am sure people will give their opinions.

For me, I don't do the sort of trips to warrant a diesel, though I have one I inherited.
It's my opinion that to make them as clean as needed they've become overly complicated, expensive to repair and a lot less reliable than they were 20 years ago, though they are far smoother and more powerful than they were back then.

I would hazard a guess with your planned use, you'll probably come to the same conclusion.

All these smaller turbo petrols haven't quite lived up to all the claims, they do tend to be a lot more thirsty than they lead you to believe and I can see why some companies are fitting mild hybrid systems to them.
I can't see the slight increase in capacity will have much effect on this, I've a 1.4 turbo petrol and to be honest, the mpg is shocking.
Some, like the Nissan.Renault 1.2 Dig-t has been a bit of a disaster as they came with a host of manufacturing problems from the off that they never quite got to the bottom of.

Most are pretty good to drive as they produce lots of torque just like the turbo diesels but don't have their emissions equipment, around town and short trips it's pretty much wasted and repeated stopping with red hot turbos can lead to carbon building up in the turbo oil feed and return pipes, starving it of oil.

Both diesels and turbo petrols tend to all use Dual Mass Flywheels that can suffer problems and more often require replacement when the clutch is due anyway, adding to costs.

The NA petrol engines tend to drive a bit flatter and suit town and sort trip driving, but don't feel out of depth cruising distances.
There's obviously less under the bonnet to go wrong as well and are generally cheaper to service as they don't require expensive oils.

Over the last few years we've preferred them in our family car to anything else as they are simpler and less fussy to run and service.
We are a bit miffed Suzuki has dropped the NA 1.6 from the Vitara as we'd planned on swapping like for like later this year, it was more than good enough to choose the same again and the actual mpg almost matches the reported figure unlike the turbo courtesy cars we'd had.

forgotmyname

Depends on the car, bigger/heavier car with a smaller turbo engine will need to be worked to keep in the powerband.

1.5 diesel with 115bhp - 260Nm / 192ft-lbs torque

1.2 turbo petrol 128bhp - 205Nm / 151ft-lbs torque

Even with an extra 13bhp it still loses a 55Nm of torque.

Herzlos

If it's a heavy car, or heavily laden regularly, then go for diesel.


Otherwise go petrol. Smaller turbos are fine, they just feel like bigger engines. They will guzzle more fuel when on boost, so you may find if you drive them hard the fuel economy is awful. 1.2/1.3 turbos with 120+bhp should be alright thought unless you're in something huge.

mac.d

Herzlos wrote: »

Otherwise go petrol. Smaller turbos are fine, they just feel like bigger engines. They will guzzle more fuel when on boost, so you may find if you drive them hard the fuel economy is awful. 1.2/1.3 turbos with 120+bhp should be alright thought unless you're in something huge.

Haven't the Fiesta's had a lot of issues with their 1.0 turbo engines? I'm looking at getting something smaller but the trend for newer models appears to be 1.0 turbo or diesel and that's it. Admittedly I'm not looking at 2019 models so unlike the OP haven't noticed a change to 1.3 engines.

andrewf75

Herzlos wrote: »

If it's a heavy car, or heavily laden regularly, then go for diesel.

don't buy a diesel now surely?

why buy something that's on the verge of being obsolete?

Herzlos

Some tiny turbos are pretty bad. The fiat 1.0T twin-air has a terrible reputation for fuel consumption whilst still having no power.

andrewf75 wrote: »

don't buy a diesel now surely?

why buy something that's on the verge of being obsolete?

They aren't going to be obsolete for a long time yet, they just are making less and less sense as a purchase. It still has it's merits for those that need them - more torque and better economy if you're doing huge mileage.

wymondham

Thanks for all the very helpful replies - The actual car I'm looking at is the new Dacia Duster. I think I'll be looking at the Tce engines since the car isn't that heavy - certainly its lighter than my current Ford Focus.

Whilst the MPG on the diesel appears good I do have a concern about the long term value of a diesel car. The need to use AdBlue also adds to the cost per mile as well as complicates things. Diesel also adds a few thousand onto the purchase price of the car so I'd need to be doing serious miles to get that back...

andrewf75

Herzlos wrote: »

They aren't going to be obsolete for a long time yet, they just are making less and less sense as a purchase. It still has it's merits for those that need them - more torque and better economy if you're doing huge mileage.

agree, but doesn't sound like they do much mileage

wymondham

forgotmyname wrote: »

Depends on the car, bigger/heavier car with a smaller turbo engine will need to be worked to keep in the powerband.

1.5 diesel with 115bhp - 260Nm / 192ft-lbs torque

1.2 turbo petrol 128bhp - 205Nm / 151ft-lbs torque

Even with an extra 13bhp it still loses a 55Nm of torque.

The new engines (1.3) have 240/250Nm torque so very close to the Diesel.... the 1.2 is an older one..

https://www.press.dacia.co.uk/en-gb/releases/230

https://group.renault.com/en/news/blog-renault/1-3-tce-a-new-petrol-engine-co-developed-as-part-of-the-collaboration-between-the-alliance-and-daimler/

daveyjp

The Renault 1.0t isn't that good - we had one and it needed a new turbo after 15,000 miles and we weren't alone. MPG wasn't too clever and it did deliver power in 'lumps', driving around town wasn't always smooth due to how power was delivered.

Traded it for a n/a petrol - far more relaxing and despite being a 1.5 better mpg.