Renault has revealed a prototype version of a lightweight diesel engine that weighs significantly less than a regular diesel engine, plus a whole range of other future technologies
12 December 2014

Renault has revealed a prototype version of a two-cylinder two-stroke diesel engine, which aims to halve the amount of space needed in the engine bay and not increase engine noise.

The engine is 50 per cent smaller than the best-selling four-cylinder, four-stroke 1.5-litre dCi unit on which it is based. The 730cc prototype unit, which weighs in at less than 100kg, is 40kg lighter than the 1.5-litre dCi.

Renault says the aim is for this engine to be around 15 per cent more efficient than the equivalent four-cylinder unit, although it stresses that this engine is not yet at that level.

Renault has not revealed any performance figures for the engine, but says it is both supercharged and turbocharged and produces between 48bhp and 68bhp and up to 107lb ft.

A company insider said the engine has been designed with emerging markets in mind and should cost less to produce and buy than the full-sized four-cylinder version due to the reduced number of parts required. However, it will still cost more than a petrol engine of equivalent power to the 1.5 dCi.

The company spokesman also said this engine should sound exactly the same as the four-cylinder version.

Currently, the main prohibiting factor is the cost of the turbocharger. The spokesman said: "We haven't invested yet, but we know how to make it." 

A second phase of development is expected before the engine makes its way into production cars.Renault also revealed a host of other new and developing technologies at its Cooperative Innovation Laboratory (LCI) in Paris. They included:

LPG/Petrol engine

A new engine due to go on sale in the coming months is a petrol/LPG dual-fuel unit. It is based on the 0.9-litre three-cylinder petrol engine found in the likes of the Dacia Sandero.

Renault says this engine is 20 per cent more efficient than an LPG engine of the previous generation, and it cuts emissions by about 10 per cent. Due to a lack of LPG infrastructure, this engine won't be offered in the UK.

Twizy Delivery Concept

Renault’s researchers have taken a standard Twizy and turned it into a small delivery truck. The prototype has no rear seat and instead has a detachable two-wheeled trailer that can carry loads of up to 150kg.

Trials are set to start in April next year before a decision is made on whether to put it into production.

Whole dash touchscreen

A revolutionary idea Renault has created is a touchscreen that stretches across almost the entire width of the cabin. It uses two small LCD screens in front of the driver for the instruments and two 76x17cm screens on the rest of the dash. One acts as a large infotainment screen, controlling the likes of the sat-nav, air conditioning and even the direction in which the door mirrors are pointing. The second screen is in front of the passenger and is for entertainment. The system can play films and music and display photos, and should be able to connect to the internet via a smartphone. It uses a similar optical system to that used by Jaguar Land Rover that allows the passenger to see what is on the screen while hiding it from the driver. An insider said the technology is ready to go into production, but a final decision has not yet been made.

Value Up concept

Autocar has also seen a concept car created by Renault called ‘Value Up’ which is unlikely ever to be seen in public. Read more about it here 

Get the latest car news, reviews and galleries from Autocar direct to your inbox every week. Enter your email address below:

Our Verdict

Renault Clio

A multi-talented contender that can stand comparison with the best

Join the debate

Comments
6

11 December 2014
The old-school two-strokes were discontinued because they couldn't cope with even rudimentary emission regulations - since Renault will obviously be targetting Euro 7 and beyond, I wonder how they've clean it up.

11 December 2014
Interesting if it's two-stroke and not just two-cylinder like a diesel Fiat Twinair. The physical size saving will come from the half-sized block - thought two stroke engines were just inherently inefficient and polluting, but seems they are making a comeback - there was a Lotus design a few years ago.

11 December 2014
Ford built quite a large fleet of 2-stroke petrol powered Fiesta 20 years ago,a good number of which I believe were trialled by the Metropolitan police. They drove well (better than the petrol Fiestas at the time), but I think the problem was one long term durability. Let's hope that Renault has better luck,because the benefits of a 2-stroke (simplicity and having one firing stroke per revolution of the engine) are well worth having.

11 December 2014
LP in Brighton - The 80 hp 1.2 3-cylinder Orbital direct-injected 2-stroke that was once shown on an old top gear episode?

Also seem to recall that the Ford Ka was originally intended to be powered by a 2-stroke petrol (a development of the Orbital) before EU emission laws forced them to abandoned the 2-stroke unit and make do with the existing Kent engine.

Read a while back that Chrysler also had a 2-stroke project going and was even going to power the mk1 Neon before emission laws killed it off.

Hope it works out for Renault with this engine eventually powering the Twingo (and related Smart models) and that other automobile manufacturers are encouraged to produce their own 2-stroke petrol / diesel engines for cars.

11 December 2014
Judging by the appaerance of camshafts at the top of this engine (assuming this is a picture from Renault of the design of the prototype) this is a valved 2-stroke diesel, like they've used on Locomotives for a while, it could have a conventional lubrication system similar to a 4-stroke which would address the emissions issue, which presumably means it only has less moving parts due to having less cylinders. Apparently this kind of engine needs the supercharger just to make it work and with just the supercharger alone is classed as normally aspirated (I don't quite understand this part of the tech) so needs the turbo to give it the extra compressed air to provide the suitable power and torque.

12 December 2014
I agree with your general thoughts here. They need the supercharger because I guess they are not using the traditional crankcase compression to provide the required air flow . I imagine they are running the supercharger at a very low compression rate to provide the 'natural aspiration' of the engine, not consuming to much power in the process. With turbo then kicking in, in the normal way. Doing this allows for a traditional crank lubrication system and will help considerably with the emissions. This also should have a huge positive effect on longevity/reliability. Quite frankly its about time someone finally did this. With some clever engine management there is no reason why this could not be both a 2 & 4 stroke engine to really bring in some savings. Given enough cylinders (say 4) and cylinder deactivation tech (ala VAG) this could be effectively a 4,8 cylinder engine in 2 stroke mode and 2,4 cylinder in 4 stroke mode if you get my drift. If you cannot get enough power and economy out of that set of options then someone is not trying hard enough.So just how long before the 1 litre porsche etc becomes the norm.

Add your comment

Log in or register to post comments

Find an Autocar car review

Driven this week

  • Lexus LC500
    Car review
    20 October 2017
    Futuristic Lexus LC coupé mixes the latest technology with an old-school atmospheric V8
  • Maserati Levante S GranSport
    First Drive
    20 October 2017
    Get ready to trade in your diesels: Maserati’s luxury SUV finally gets the engine it’s always needed
  • Jaguar XF Sportbrake TDV6
    First Drive
    19 October 2017
    The handsome Jaguar XF Sportbrake exhibits all the hallmarks that makes the saloon great, and with the silky smooth diesel V6 makes it a compelling choice
  • Volkswagen T-Roc TDI
    First Drive
    19 October 2017
    Volkswagen's new compact crossover has the looks, the engineering and the build quality to be a resounding success, but not with this diesel engine
  • BMW M550i
    First Drive
    19 October 2017
    The all-paw M550i is a fast, effortless mile-muncher, but there's a reason why it won't be sold in the UK