1989 110 - 2.5 petrol vs 300 Tdi - Pros and Cons?

We bought our 1989 Defender 110 with plans to swap out the 2.5 petrol engine for an entire 300 TDi turbo from the same seller, who is a good friend of ours. The 300 TDi package is complete with gearbox, intercooler, etc, and reportedly in great shape and never even opened up to work on. The only problem it had was the turbo was beginning to get a bit weaker, and to overhaul the turbo would also require an engine overhaul, so he just pulled the whole thing out and imported a newer engine. The good news for us is that there is no ECU, so electrically, a pretty simple swap.

While waiting on Kenya paperwork issues before the engine swap (it's glacially slow for anything related to registering/changing vehicles), we had to overhaul the petrol engine just to make it marketable and for us to even use while waiting. It is now running great, but guzzling down the petrol!

So we're at a crossroads...keep the petrol, or install the 300 TDi? Fuel economy is becoming a very big negative for the petrol. I love the acceleration, but it still doesn't have as much power as we would like on hills at >40 kph speeds. (And the tarmac roads around here have some very steep climbs!) I've heard differing opinions how much power the 300 TDi has.

I know there are plenty of other considerations, like tendency to overheat, etc. Let me hear from you all - pros and cons?

A turbo in need of replacement and an engine overhaul could be an expensive repair down the line. The petrol engine is nice and simple and there's very little to go wrong with it. Now its been overhauled it should basically last forever if you look after it.

Is LPG readily available where you are? If so that could be a viable alternative to the fuel costs. Bear in mind though, that you can buy a lot of petrol for the cost of rebuilding a tdi or fitting lpg.

What sort of MPG is your petrol getting and as for acceleration I reckon a 300tdi would beat a 2.5 petrol although it would be like a snail versus a slug. Also you wouldn't need to swap the gearbox but you may need to move / weld in new mounts for the engine

3ootdis dont have a tendency to overheat , unless the rest of the cooling systemm has been neglected , I ran a 300tdi 130DC HCPU in Australia and it coped with the heat no problem even when running at 7450kg train weight with the aircon on . The tdi will be as quick as the petrol , and will give about 29mpg .

I get 35 mpg from my 300tdi, which I installed when I rebuilt from a 1992 2.5 petrol.

I sometimes wonder if I should have kept the petrol engine as it was so refined in comparison to a tdi, but I enjoy the diesel economy.......


Paul

Thanks for the inputs all! We've been oscillating on this nearly every day, so your thoughts really help. I now feel better about some of the potential drawbacks of diesel. It's a tough choice!

300 110 is alright in modern traffic i reckon. equiv to a lil 1 lt thing

I had a 2.5 petrol 90 and it was great fun. I could sit in 4th gear and it pulls really nicely on low revs, but the cost of fuel is why I sold it. I was spending around £200 a month on fuel, with my 300tdi 110 costing me about £100ish a month atm. Speed is also noticeable, I would struggle along at 60mph with the petrol, but the 300tdi can cruise on the flat at 80mph.

Swings and roundabouts!

Tripp said:

Swings and roundabouts!

Click to expand...

ah mine just rolls at roundabouts

Keep the petrol... diesel is horrible

Sounds like you really need to "do the math". A petrol will always be smoother and quieter to drive, but fuel costs (in the UK at least) make them a fun day only vehicle - unless you are wealthy/fanatical! Look at how many miles you are going to do in the next 5 years and how much fuel will be saved, against the cost of the engine change (and turbo replacement).