Which turbo diesel for best MPG and ease of fitment?

[Zebedee]

I'm still after fitting a turbo diesel into my 73 bay westy but after driving a 1.6td t25 around for a while and seeing the MPG i got in that i have decided the passat unit i was gonna use doesn't give the best MPG in a bay sized vehicle.

I'm now looking into alternative (non VW) turbo diesels and wondered what sort of MPG you can get from a 1.9 pugeot and the 1.8 td escort unit and which is the easiest to fit?

[Bugsy_malone 666]

what type of MPG are you expecting to get?

bays area bit lighter than t25s i nthe same way splitties are a bit lighter than bays. during the summer for a while i had a 1.6 non turbo diesel out of a T25 in my bay and people with T25s complained no end of how bad that engine was yet in my bay it was on pary with my 1600 petrol engine and it didnt drive too bad. cruising at 55mph i was getting around 43mpg giving a diesel more stick you'll get it down to the low 30s, but thats with it being connected to a 1600 petrol gearbox.

what you have to do is look at the whole package a bit more carefully rather than just think a 1.6td vw engine will be worse on fuel than a pug/ford engine.

modern vw engines in passats achieve something like 50-55mpg and you have to consider the bays a fair bit heavier. part of the package you should look at when you do an engine conversion should be a gearbox upgrade to, looking for sometihng like a 2litre bay box or a 2/2.1 T25 box, connected to a 1.9TD aaz which i suspect depending on driving style would give you 40-50mpg.
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Second Gear All The Way Baby!

Doing Thing Differently.

[Zebedee]

The 1.6TD T25 i drove was getting about 35-40 to the gallon which isn't too bad i suppose given the size of the vehicle but i was expecting more as the same engine in the '92 passat estate i had (though it was intercooled and gave 80bhp instead of the 70 in the bus) did 50-55.

It was just with the cost and work of fitting the TD engine i was hoping to get a huge difference in MPG. I get around the 28-30 mark in my 1600 bay as it is.

Won't fitting a 2litre 'box only make about 250rpm difference at the same speed to using a 1600 'box? The ratios aren't that different. Are they?

[Bugsy_malone 666]

well the thing you can see there is the fact that you have a difference between a passat an a T25, theres going to be a difference in the gearing on the passat 2. A T25 is a van so will be built to haul huge loads, the 1600bay gearbox has slightly higher ratios than the diesel box in the T25, by my reckoning the final drive on the t25 diesels would be good for climbing mountains!

Not sure if the turbo diesel might be a bit better fuel wise than the no turbo, but its also the torque, you'll have quicker acceleration than a stock 1600 bay and you'll be able to haul more gear while getting more MPG.

with the bay diesel conversion it can be done relatively easy with the cooling system being the biggest headache depending on your approach, I used a T25 bell housing/sump/engine mounts and it all goes in fine with minimal work, to be honest time wise i had the engine in place in a week if i had been working on it full time ( i did it over about a month of weekends i think) my max mpg in the bay used to be 29mpg doing 55mph it then went up to a max of 43mpg with a minimum of 32mpg, when i did bugjam on it I did around 800 miles and worked out that I saved about 10-20 quid in fuel, even though diesel was a poo load dearer than petrol, over a year the conversion pays for itself, you have heating in the winter (unlike my bay with its ac lump at the minute) and an option to run it on wate veg oil if you fancy.
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Second Gear All The Way Baby!

Doing Thing Differently.

[Zebedee]

Theres something in your post i'm not sure about.

This thing heating? Thats a thing of myths and folklore isn't it?
Something to tell your kids to make them behave? "If you behave i'll put the heating on" kind of thing?

I'm thinking of slinging (not literally ) a radiator under the bus between the chassis rails as theres a nice big alloy cored radiator sitting in my mates shed he's not using and it looks like it could fit and i might get it cheap.
The idea of heating in the winter is really winning my missus over.

I suppose the frontal area of a T25 or bay and the drag is a lot larger than a passat too plus the extra weight would make the difference.

[jp]

aerodynamics is probably the main key for your difference in MPG between passat and bus. I used to get around 40mpg out of my non turbo 1.8D Escort lump in my bay with a pretty heavy right foot a bit more on motorway journeys at 60-70. My 1800 ac engine was lucky to return 20mpg (same heavy right foot used)

I think you pay for the reliability more than anything I found I was always tinkering with my AC to get it work right and having to service it every 4k


As for the heating and demisters that work surely that can't be so !

As for using other Diesel engines I'm sure they're much of a muchness in terms of MPG... In the future I hope to use the engine from my daily 1999 Passat TDI as I think that would work quite nicely in the bay.. won't be for a few years though..escort TD will be going in when it's back from the spray shop.
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1971 Devon Bay with 1800 Ford Turbo Diesel Engine (wip)
1983 VW Golf GTI Campaign
1979 Mini 1275 GT
2013 Scirocco TDI GT

[Zebedee]

I suppose a brick shaped vehicle wouldn't cut through the air with as much ease as a car.

40mpg is not that bad if thats with a heavy right foot.
I think i could live with that.

Driving a 1.6 bay westy means i'm always driving with my right foot to the floor and when i'm driving my 8v gti engined passat it does get a thrashing every so often so i might have to reform my driving habits to get better MPG.

Is the TDI in a 1999 passat before all the electronics for fly by wire throttle etc were fitted?

[jp]

[Zebedee]

Fly by wire is a bitch.

My mate was trying to do the same to a T25 syncro with the 110bhp TDi motor out of a golf GT TDi and he gave up because he couldn't sort out the throttle.

Ended up with a 80bhp 1.6 passat motor with the 1.9 gold bottom end instead and we tuned it up with montego turbo, tweaked injector pump, custom s/s exhaust and K&N filter. Made 102bhp on the rolling road.

[andymacdonald30]

I have a pug 1.9 n/a in my t25 72 bhp
The motor came from a 305 pug with 90,000 on it
I have a turbo diesel gearbox and it will push the old girl along at 75 mph
At max speed it gives me around 35 mpg but sit at 60 to 65 and it will go up to over 40 mpg

I did look at a 1.9 TDI from golf but it sold on flebay for 515 pounds
And the pug motor sold to me for 75 pounds

I did pick up a 1.9 TDI pug motor 94bhp for 90 pounds but still need to get the engine mounts sorted
I have all the bits I just need to get my ass in motion and make them
Well it has been a little cold recently

I was lucky as my t25 came with a pug conversion kit on it
And there seems to be a bit of a problem getting the kit now
There have been several people asking for famous Phil but he seem to be missing
Unless he has now reappeared

So that is another factor to take into account when deciding
The ford conversion kit I think is available I am sure I have seen details of it on the ford section

Any way good luck

And if all else fails Make me an offer on my 1987 diesel caravelle with a home brew camper conversion

PM me if you are interested

Andy
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2002 T4 2.5 tdi
1987 T25 1.9 D

[andymacdonald30]

Reading through this again I suddenly realized that fitting a petrol gearbox to a diesel is not the best way of achieving good mpg
The diesel gearboxes are higher geared due to the lower revving from a diesel motor

I am not very knowledgeable with ref to Bays so I am not sure if there is an issue in fitting a T25 diesel box
But fitting a diesel box should give a better all round performance and MPG

Andy
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2002 T4 2.5 tdi
1987 T25 1.9 D