Thread: 3.9 V8 vs. TDI - does one generally last longer than the other?

Originally Posted by chazza

Interesting post Shaun.

Penrite 40 has only six-tenths of a gram more zinc than Penrite 15, which is the oil to use for the V8 as recommended by Penrite.

My new cam, which I am yet to install, came with a tube of Penrite cam-lube. Have you had any experience with it?

Cheers Charlie

Penrite cam lube is fine, but I spray cams with Molycote as well first. The more zinc you can get to bed a cam is the go. You can buy bottle of Crane or Comp cams ZDDP oil add as well if you are worried, Most US cam manufactures reckon 1000 parts per million Zddp. Any Penrite oil, ie 30, 40 50 have heaps.

The original post asked about whether a TDI or a V8 would last longer.

I guess the orginal question was someone trying to figure out what model would be the cheapest to own in the long run. For me what I would ask myself is, given you can now pick up second hand D1's so cheap which engine is the cheaper to change over if the orginal blows up? The answer from everything I have read is the V8 by far.

There are so many second 3.9's around that no body wants that for me its just a case of shoving another one in if and when my 3.9 fails.

Having seen TDI's selling second hand for more then most second hand Disco's says to me you don't want to have your TDI fail on you or it could cost more then the vehicle is worth.

Swings and round about really, the V8 costs more in fuel but its cheap to fix or change the engine, the diesel is cheap on fuel but can be scary to get a replacement engine.

For me personally I like the V8 rumble and the power, the diesel just doesn't have either so I'll put up with the higher fuel bills.

cheers,
Terry

With the D1 the pick is the V8 for me on LPG. The Tdi is a real rattler and gutless around town for me. My mate had a 96 Tdi in very good nick and I had an identical green 95 V8 Auto on LPG and the two were like very different vehicles. He loved going in mine. We both tow the same weight boats and I used to have the odd drag and thrashed him silly.

My 95 has done 280,000 and it still pulls very hard. I have only ever used Penrite HPR 30. If she has wear in the cam, it is not affecting performance.

Cheers

To me there appears to be a lot more questions/faults on this forum for the TDi than the V8.

The tdi looked after properly will last longer for sure.
Having said that, the 200 & 300 tdi's do have lots of traits, and cost big bucks to fix.
There is nothing like a sweet sounding V8.
V8's also have their usual traits, head gaskets etc etc.
At least you can pick-up a second hand V8 for $800.00 or so, or even a complete car for that.
Diesel engines are well up there to replace complete, or to rebuild.
One last thing, if you are a V8 owner, how do you afford the fuel, and rego atm

IME the bottom end of the V8 is good for 400-500k km if looked after. The heads and cam seem to need an overhaul every 150k km.

The Tdi should do 400k km + if the timing belts are replaced regularly and the engine is not cooked or suffers from the "soft head" issue. Rick130 has suggested the bottom end of the tdi is the weak point. Though others seem not to have experienced this???

So they seem about equal overall in terms of longevity. Just that the Tdi has no electrics, and half as many of most components - so easier to work on.

, the closest thing to a computer in my tdi is the clock

Dear Busman, you ask how we afford the fuel and the rego for a V8? Its old farts perogative, V8 is on pensioners rego and it runs on LPG, which if you work it out, is cheaper to run than a diesel, depending on where you fill up. In Brisbane I pay 67.9/l for LPG (which includes the 2c/l discount at bee pee) which at 19l/100km works out to be $12.91 for 100km. Diesel is 149.9/l which if you get 10l/100km works out to be $14.90. I don't mind stopping more times to fill up, I see more and rest more. If you drink water while you are driving you still have to stop every 2 hrs. Think about it next time a V8 goes past.