CRD Fuel consumption

[jakeslouw]

To me it seems people put a huge price tag on consumption. Too much so.
It is not only the difference in price, but also the maintenance costs thereafter that is cheaper with petrol.

Absolutely. Also the POTENTIAL for a catastrophic failure: the 4.8 very rarely burns holes in the pistons due to over-fuelling, you can't say the same about a turbo diesel.

[ra_01]

Good day gents.

This is very interesting to me.
I always thought that the Crd Di would have slightly better feul consumption than the Di and then the improved reliability of coarse.
In fact i have been waiting for the right Crd to come along so i can change to a Crd but this makes me seriously rethink that having seen the actual figures from you guys.

I have a series 3 DI (2004) and on a round trip of 1144Km fully loaded towing a car trailer with a 850Kg racing car, feul and spare tires etc. I got 8,5km/l that is traveling at 100-110 and even 120 when the roads alowed.

On another round trip of 1660 km to Santa Maria in Mozambique also fully loaded but without a trailer i got the same consumption but this was traveling at 120km/h as much as the roads alowed and it also included a section n of "twee spoor" thick sand road of 180km through the elephant sanctuary to Santa Maria where i had to drive in low range quite a bit as it did not have enough power in 1st and 2nd high range going slow, it would bog down and stall. The refuel including that sand section consumption dropped to 6km/l if i recal correct.

Normal driving without a load or towing i have managed high 9's at times.

This makes me think a 4.8 might be the better option if comparing to a Crd. Taking into acount the power, reliability, and the price difrence between the Crd and a 4.8. As of late should a Crd come into the market it also has huge price tag.

That was my observation. Consumption of NON-CRD is descent and consistent, perhaps comparable to a 4.2 diesel (I stand to be corrected). However, there is that reliability issue which needs to be looked into.
What ever Nissan did to make their 3.0lt reliable by introducing CRD; It made an impact on consumption.

With factory 4.8 auto, its difficult to get the figures we get, but after some upgrades e.g. diff ratios, exhaust etc better consumption can be achieved; although not as good as a diesel, but close. It will probably workout in the long run for some folks including me.

[jakeslouw]

I'd still say a well sorted TD42 with Variable Vane Turbo would be the dog's bollocks. Power and good fuel consumption in an unstressed delivery.
I've always thought the ZD30 was a little small for that application.
They were even too scared to use it in a proper truck body, whereas Isuzu, for instance, ran the 4Jxx engines in full size trucks as well as passenger vehicles.

[Peter Connan]

The problem is you need a computer to properly sort a Variable Vane Turbo. Which negates the one thing I like most about a TD42.

I know I'll never have the dosh to fiddle with this, but I have been wondering about a two-stage system comprising a supercharger first stage and a turbo second stage...

[jakeslouw]

The problem is you need a computer to properly sort a Variable Vane Turbo. Which negates the one thing I like most about a TD42.

Reenen will argue with you about that. You only need a boost-based activator. But anyhoo.........

[JoshJ]

I owned a CRD since new for 3 years. 2inch lift. Roofrack. Bullbar, winch, rear bar, 33inch tyres. Drawer system. Sliders. 3inch exhuast from turbo. 10inch fan under intercooler. Dastek chip. Drove it for +-73000km. Overland trips. Town trips. City trips. My average over the 3 years was 7.5km/l that included a 7% odo correction. Cruising when on holidays. Driving to get there for the rest of the time.

Now you go calculate the cost difference off the 1.5km/l gain on average, over 6000km overland trip. It will pay for your accommodation.

[ra_01]

I owned a CRD since new for 3 years. 2inch lift. Roofrack. Bullbar, winch, rear bar, 33inch tyres. Drawer system. Sliders. 3inch exhuast from turbo. 10inch fan under intercooler. Dastek chip. Drove it for +-73000km. Overland trips. Town trips. City trips. My average over the 3 years was 7.5km/l that included a 7% odo correction. Cruising when on holidays. Driving to get there for the rest of the time.

Now you go calculate the cost difference off the 1.5km/l gain on average, over 6000km overland trip. It will pay for your accommodation.

Hi Josh, been a while. Welcome back.
Your set up sounds similar to my mine, except the RTT. Do you think you would have averaged the same if you had a 95kg RTT on the roof?

[JoshJ]

Yes, its been awhile. Thank you.

Definitely not. I once did a test. Running from secunda to jhb. 2 consecutive weeks. One with the roof rack. One without. And the rack reduced consumption by 0.7km/l. So a RTT will have a great impact. This was driving normal not exceeding 130km/h.

In general the slower you go the less impact wind has. The amount of energy that the car needs to produce to maintain say 120km/h instead of 100km/h is huge. Specially big square vehicles like ours.

I once drove to the kgalagadi from secunda with a 4.0 Navara. Had a fully loaded trailer at the back 5 adults. I ran 110km/h and got 5.5km/l at every fill up which was around the 350km mark. Then I tried running one at 100km/h. I go 7.1km/l.
I couldn't believe it. But it was noticeable. The car shifted way less between 4th and 5th at the lower speed.

All of the above doesn't consider head winds and the direction of impact on the car.

A diesel wil always win the economy run. Theres just no going around it. It it comes down to the low torque I would recon.

A petrol may always win the overall ownership cost run. But never the feul consumption run.
Petrols are way cheaper to run, all things considered over a 1 or 2 year calculation.