What modern technologies have made a significant advancement in fuel economy?

[BLUE STAR]

Totally agree

Tailgating an Eddie Stobart down the motorway can add 4 or 5 mpg to my 2.8L diesel Wrangler 

Until he turns off for a break 

[V]

1 hour ago, Caroline12 said:

Heavy vehicle = worse fuel efficiency

Not always true, it depends on the vehicle. A diesel-electric locomotive hauling a train of twenty high capacity tankers is likely to use less fuel than sixty road tankers hauling the same total volume of the same liquid the same distance. Rail transportation uses less fuel than road transportation on pneumatic tyres because of lower rolling resistance.

[Raakhee]

3 hours ago, BLUE STAR said:

Totally agree

Tailgating an Eddie Stobart down the motorway can add 4 or 5 mpg to my 2.8L diesel Wrangler 

Until he turns off for a break 

Glad I'm not the only one tailgating an Eddie Stobart. Usually when I'm coming home at night from Tidworth, I find one on the A303, match his speed and just follow along until the M25 exit. No need to manage high beams and low beams as his back is lit up like a Christmas tree

[JimC]

Just thought I would throw this into the thread.  

 

https://www.curbsideclassic.com/blog/junkyard/curbside-recycling-e-waste-special-why-did-ford-send-a-batch-of-brand-new-2017-ford-focus-evs-to-the-junkyard-in-2022/

Its about 12 brand new Ford Focus EV's ending up in a US junk yard and the State of California enforcing a decree that the six most popular automakers in the California new car market had to produce and sell a certain number of zero emissions vehicles in order to keep doing any business at all in the state.  

 

 

[V]

I can understand why that happened, but they could have just as easily given them to charity instead of scrapping them. So the CO2 emission from manufacturing those 12 EV's is magically wiped off the atmosphere because they are claimed to be 'zero emission'.

[V]

I had a good look at FreeValve last week and 3D printing sand cores and moulds for metal casting. After watching videos of a FreeValve conversion on a Mazda Miata (MX-5), I had the idea of converting an existing 4.0L into a 24 valve cross flow engine without camshafts with a custom head swap. Inlet and exhaust manifolds would also be necessary. Individual throttle bodies from a motorcycle would be a sensible enhancement as would dry sump, electric hydraulic pump, coolant pump, fans and fan clutch.

 

While looking more into this I found that in Argentina, a special race series uses custom made 24 valve, DOHC heads for the Jeep 4.0L .

I think for a custom cylinder head to deliver the best possible fuel economy FreeValve is the way to go as it avoids all of the mechanical losses of a crank driven valve train. Obviously, the Argentinian head is for power. FreeValve would make a similar head work for power, torque, fuel economy and lower emissions through independent valve control. Being able to operate with 2, 3 or 4 valves at any time according to programming is a huge advantage over camshafts.

[Caroline12]

On 26/10/2022 at 22:31, V said:

Not always true, it depends on the vehicle. A diesel-electric locomotive hauling a train of twenty high capacity tankers is likely to use less fuel than sixty road tankers hauling the same total volume of the same liquid the same distance. Rail transportation uses less fuel than road transportation on pneumatic tyres because of lower rolling resistance.

I was only thinking of road vehicles with tyres, anyway ships trump trains for fuel economy

[Caroline12]

Personally if it was me, I would consider an replacement engine, modern engine.

for example a second hand wrangler engine and gearbox, 2.0L 4cyl petrol turbo or even a diesel version. The xj is lighter than the Rubicon JL and can handle the larger wheels etc. If you can weld and have the workshop capabilities, you could fit and mount the engine gearbox with mounts. It would be better if the engine fitted to the original gearbox, but I doubt it would, just to be difficult. 
 

the engine in your XJ is not as powerful compared to modern engines, sorry (20 years of engine technology), but the new wrangler engine has 100bhp more than your engine and a 2.0 litre. Don’t know the torque.

so potentially more power, more torque and better fuel efficiency. Easier for lub oil, servicing and spares.

I would consider speaking to ACD Lancashire (Jeep breaker) +44 7749 431847 and seeing what engines they have at different prices. They may even have a 4.0L xj engine on the shelf to play with
 

I appreciate it’s not the original 4.0L 6cyl engine. But sometimes a compromise is needed. It’s an option

[stewart]

Check this out the long awaited Straight Six hurricane engine 3.0L 500hp ! https://www.autoblog.com/2022/03/25/stellantis-hurricane-i6-hemi-replacement/