Project: the long distance 928

[Pauwl]

The issue at hand:

1984 928S (Auto) Schifferblaumetallic/blue leather, around 250k (km) on the clock.
Used to be my wife's ride, as I live in France, work in Holland (650km on-way), and travel there & back once a week.

The wife's moving on to another car, so I get the shark during the week now as well :-)

Given I run around 100k km/year for work, I'm looking for a nice, comfortable drive, reliability being an issue of course as well.
It goes without saying that I'm looking to have this all in the 928.

So here's the thing I want to do: Make a distance drivers' 928.

My criteria:

#1 Pleasure
#2 Reliability
#3 Comfort (7-8 hours drive at a time), so things like engine/road noise need to be addressed, but so does cruise control (not yet installed)
#4 Fuel efficiency
#5 Practicality (not quite sure what I mean here yet)


I'm banking on #1 being the same as it is now, and driving the distance in the shark is wonderful - excellent roads in France, a pleasure to drive.

I've looked about for threads on the above, but couldn't find what I'm looking for.

Any advice on achieving improvements in the criteria?

thanks,

Pauwl

[Danglerb]

The 928 as it comes from the factory is finest long distance driving car ever made, and very comfortable even after many hours of driving. Give the 928 a try and it may spoil you. If it doesn't feel amazingly comfortable and fatigue free, something may be broken, supports inside the seat etc., but all items that can be fixed.

Fuel efficiency I don't see changing much without a motor swap. People have done both diesel and electric conversions, something with a hybrid might be interesting, but I'm not sure where practical might pop into the picture. I think a lower flow resistance exhaust without increasing loudness is possible, and some gains might be found using modern fuel injectors. You could also consider a 2.20 differential ratio if yours is the 2.69 and that might help both noise and economy.

My recommendation would be to leave it as original as possible, add a sound system to your liking, and keep the PM current and enjoy it. A bit higher fuel costs than some options, but overall not uneconomical compared to similar levels of comfort in a newer car.

For road noise, depends on your sensitivity, but it can be reduced with some careful sealing and insulating various areas. There is a long thread that could be searched out that goes into some detail on what to try.

Driving that far demands a higher level of preventative maintenance than might be done for a car driven only locally, and I would also put together a basic kit of tools, information, and spares. Like noise, thats a longer topic than one post will hold, but there are good threads with details.

[Pauwl]

We've had the S for almost 10 years now, so I really do appreciate the ride.

However, in all those years we've done about as many miles as I want to put on it per year now. So that's why I want to see what I can/should do.

I've noticed on some sites in the DYI bits people mention the recommended (by Porsche and by themselves) replacement periods are for parts like timing belts, fuel filters etc.

Are these in the workshop manual somewhere, or is there a lists I can look at to see what kind of work I should be doing every 50 000km or so?


Pauwl

1984 928S - hit 250km on F1 track in it Dubai 2004

[ROG100]

To maintain the "long distance" pleasure on your autoroutes look at the Motor Mounts. They probably need changing and will change the feel of the car significantly. After market MM's are available for not many Euros.
Also ensure your ride height is correct and that the shocks are in good order.
Best,
Roger

[Nicole]

Hmmm... so you have to drive in France, cross throuch Belgium to get to The Netherlands for work. All countries with very strict speed limits. Does the car ever get to stretch its legs beyond 120 km/h (75mph)?

[Pauwl]

Knowing where the fixed radars are is of course not illegal.
Having a radar detector is of course...

Depending on the traffic (i.e. thursday nights = none), it's comfortable to cruise for a few hours at around 150km/hour. The speed limit is 130, so the fine is not all that high.

The nice thing about the route I take through Belgium is the rolling Ardenne mountains, where you can have quite steep uphill stretches that last a few km's. I love it when the turbo'd boy racers pull up next to me (I'm cruising at the speed limit) at the bottom of a hill.
It's a question of a big, old ('84) V8 pulling uphill with 310hp against the small turbo of some little nipper next to you. They run out of puff before the top of the hill, and of course the shark just goes on accelerating :-)

They catch up and whizz past again when I slow down going downhill. I think they feel they win then.

It's not great for the fuel consumption, but it brings a smile to my face every single time. Priceless.

[Pauwl]

I wonder if anyone has seen this or has any experiences with anything to reduce fuel consumption.

looking for anything, could be exhaust, intake or whatever.

I'll be using about 10 000L of fuel a year on my 100k km run, so any improvement would be great.

[Danglerb]

10 KM/L is about 24 US miles per gallon, a very typical consumption rate for highway only driving. Nothing simple or cheap is going to significantly improve that. Keep it in good tune, tires properly inflated, drive smoothly at efficient speeds, less than 120 KM/H or so. Some people report low oil pressure at idle rpm when hot using low friction oil, but lower friction can slightly reduce fuel consumption. 2.20 differential ratio can help, removing excess weight also helps.