Hi, I'm new to the forum and I'm currently looking to buy a 2017/18 Discovery. I'm looking for some advice on weather to choose the TD6 option vs. the regular V6 Gasoline. Would appreciate any inputs on reliability, maintenance, and performance?

 

I work on tier iv diesels as part of my job description... whether it be a volvo, cummins, perkins, whatever... i steer clear of diesels unless the application absolutely requires it. No matter the brand, new diesels have been regulated to being nonreliable. When we bought our disco 5, diesel was an absolute must not have for me... I'm sure there will be differing opinions.

 

thanks for your reply, can you explain why? I don't need it for application purposes, was thinking it might be more reliable and better mpg?

 

You are thinking it would be more reliable because years ago (say in the 80s) they were more reliable as they were very simple, they didn’t have ignition systems for example and they weren’t turbo’d either, they weren’t even fuel injected and had no computer.

Now Diesel engines have extremely high pressure fuel injection systems with injectors manufactured in clean room conditions (think those Intel guys in those protective suits) often directly injecting into the cylinder which means obscene conditions to endure, plus they are turbo’d with even more plumbing and higher cylinder pressures, complex computers and the associated wiring, and all sorts of systems designed to filter their emissions for environmental and health reasons.
In short, they are just as complex if not more complex than a gasoline engine and that complexity and stress brings reliability issues.
If you do lots of short journeys you are more likely to have problems with a diesel. But if you are doing lots of short journeys I’d argue you don’t need a diesel as clearly fuel consumption is not an issue. And you’d better be doing a lot of miles to make up the increased cost of the fuel and the engine.
If you regularly tow or most trips are long distance then a diesel is a good choice. In all other cases I would suggest you get gasoline.
I’m not knocking diesel, but like everything in life and engineering it has its pros and cons and and just as I wouldn’t recommend the gasoline model if you do said towing or big mileages via long trips, I wouldn’t recommend the diesel for the opposite. The right tool for the right job as it were.

 

That pretty well covers it... as well as: the DEF systems are unreliable no matter the brand... I did a cummins and a volvo def head last week. ( I'm an electric forklift tech but have been pulled in to the diesel world as well because typical diesel techs can't deal with the canBUS and sensor/controller setups). These were machines in an application that needed to be diesel. Like I said, if I didn't ABSOLUTELY HAVE TO HAVE a diesel... I would avoid one, regardless of manufacturer.

 

Well, I'll just offer up a non-professional opinion here (and certainly not to take away from the above expertise).

But I have a Td6 and love it. Yes, I drive long distances multiple times a year (Dallas to Savannah or Clemson), but it's been rock solid for 50k miles so far and the performance is on par with the the petrol models as far as acceleration.

Maybe I just got a good one, but I'd buy one again in a heartbeat.

 

Both opinions are helpful. I drive most 80+ miles when I drive so maybe a TD6 might be a good option.But I hear the other comment too...What MPG do you get on average with your TD6?

 

I'm usually averaging about 27 or 28mpg on the highway and I'm don't have a light foot

 

with our gasser and heavy feet, I'm assuming the wife and I don't even hit near what is projected for our gasser... I'd love to drag race you though from a stand still and some various roll races though lol.

 

Fwiw... in my world tier iv problems are 95 percent DEF issues and regeneration issues caused by various sensors, which stops auto regens and causes multiple issues, and NOX sensor issues.... the injectors are surprisingly reliable for running 24,000 psi (yes 24k). Fuel metering valves and injector pumps are better than they've ever been and I typically only see issues at high hours AND environments that are dirty and cause fuel contamination. Sensors dont scare me a buit and gas engines have tons of them as well... it's really the def and regen systems that are making tier iv diesels the nightmares that they currently are.