For the hypermilers.
 

ATM, I'm running my GV with 2.8 CRD engine with IOD fuse "off" as an experiment. As the mpg. computed readout zeros every time I stop engine, these figs. have become glaringly obvious. I have my own separate digital temp. gauge on cyl. head.
On the same level road at 30mph, the following.

33.4mpg. at engine temp. 75*C
13mpg. at engine temp 25*C.

The fig. does not start getting better until the engine is well above 60*C.

Leedsman.

We always agreed on this hence the winterizing thread !

I read that Renault have brought out a 1.6dCi diesel that employs steel pistons instead of the usual aluminium. As the expansion with heat of steel and cast iron (the liner/block) are near identical, the system can be made with less cold-clearance between piston and cyl. resulting in a modest fuel consumption drop of 2%. I've had a Renault diesel car and can confirm they are best at diesel fuel consumption anyhow.

As the majority of cold engine friction is in the bore/piston area (around 70% when cold), Ford tried teflon-coating the bore, and it worked -- but with a major snag -- the coating wore off very quickly.

I've read claims that a friction modifier (as used in the ATF for autoboxes with the semi-slip wet clutch around the torque converter, preventing shudder/judder) can be used as an engine oil additive to reduce cold friction, but I'm skeptical. At least this stuff shouldn't clog the oil filter.

Leedsman.

So I'd be better getting under car where Auxiliary heater was and fit this 240V pre heater I've got, and fit it in its place. Not sure if you can still buy these Kenlow heaters as this one is about 20 years old.

- for gods sake SHhhhhhhhhhhhhhhhhhhhhhhh !
- TimmyTim will be scraping it off his wife's frying pan as we speak and putting it in his engine oil
- then its to off to a main dealer to drain and flush the AT-203 from the engine & gearbox and fix the wife's frying pan
- stay away from fluid design, most scientists and professorial nuts are no good at it in ATF type situations, why think we would be ?

Yes goggsie, my Webasto was chugging away yesterday even though it was not really cold. The one-box monospace at 4,000 litres take some heating. I'd rather use 0.29l/h supporting the engine temp than 4 times that l/h rate waiting for the engine to warm up unassisted. It must be scary for those without a supplementary heater and their cabin heater full belt keeping the kids warm and demisting the glass. Derv is totally reliant on the initial compression stroke raising the gas temperature in the cylinder for spontaneous combustion. That's sometimes why uncared for uber high mileage diesels with impaired compression struggle to get enough compression to create enough heat to create an explosion.

A good tip, you have choices, and a second hand purchase would be the same cost with and without a supplementary heater. So given the gift of choice and a five month UK winter I'd pick one with. Diesels are totally reliant on the heat generated by the compression stroke, that's what spontaneous combustion is. Which is also why older high mileage cars with some loss of compression its more difficult to make a compression temperature sufficient to start the car.

http://www.kenlowe.co.uk/images/06.gif

The DIY fitting for the 240v Kenlowe is here mate !

Sure thing, if you already have an electric coolant heater, fit it immediate, it's already paid for. It will certainly save diesel, and get you a warm heater straight off. About 2Kwh is about what's needed. Let us know when fitted and the savings?

Leedsman.

Lol:D To late! Already got all of the Mrs teflon off and it's now swimming in the engine oil! Smells like chips shop when she drive's off down road! :eek: Is this normal? :p

We always knew that diesels had to be upto running temp to get the best mpg! But the difference between the two quotes are staggering! Good work there mate. Glad that our van has the Webasto heater singing away like a jet engine about to take off! :cool:

This is a very good read for hypermilers interested in diesel cold-running economy.
It's not overly technical or mathematical, and explains why about the only way to improve cold running economy is to heat up the engine before you start. The losses are; partly increased engine friction; partly increased oil viscosity; and partly increased combustion temp. losses to cold cylinder walls.

Internal combustion engine cold-start efficiency: A review of the problem, causes and potential solutions

Leedsman.
ps., One little trick for shortening the warmup time is to drive for 5mins. or so to a shop, get out and do a little shopping for 5 or 10mins., then upon returning you'll find the engine temp has increased on its own, because stored heat from friction in the bearings has circulated to the coolant, and the engine oil has heated through.

ps. #2. Re. my mod. for restricting cold airflow through engine bay -- throughout the summer, the main restrictor behind the front grill did not need to be removed. The lower, cowling restrictor did need to be removed now and then. ATM., with current temps., the cowling resistictor is in use all the time.

............................................ :D

I promise not to mention this Kenlow heater of mine again until I've got it fitted. :p But fitting may take a long time as its continually raining in these woods and its now Winter . Brrrrrr...:eek: