Radiator Blind

[Wass]

Our other car is a Prius and some time ago I mentioned the subject of radiator blind on their forum and it turned out that some of the members routinely used them in the cooler weather to allow the car to warm up more quickly and run at a temperature which would be closer to the optimum design temperature.

The consensus appeared to be that to blank off all of the lower grille and half of the upper grille was perfectly accepteble in cold weather. One of the forum actually reckoned that this would be ok up to ambient temperatures of 15 degrees centigrade. I suppose when you consider that these car will run quite happily in ambient temperatures of above 40 degrees centigrade, you can see the sense in this supposition.

I decided that i didnt want to get quite so radical as blanking off any of the upper grille but I did blank off the lower grille with a piece of 2 mm UPVC sheet which I made from taking a cardbord template off the lower grille while it was dirty and wet. ( I pressed the cardboard up to the grille and got a mucky wet outline of the grille printed onto it). I then bought a small Lexus transfer and applied it on the top left corner and hold the blind onto the grille with white tie wraps.

Initially , the car looks a bit odd but it does work so to my mind its a worthwhile modification. I have run with this in ambients up to 18 degrees centigrade with no trouble at all. I still havent heard the cooling fans cut in yet so it seems that the design parameters of the Lexus arent being stretched.

I would estimate that fuel consumption improvement is around 10% with my latest fill up acheiving 68.2 mpg (real mpg, the dashboard was telling me 73 ish mpg)

I have attached a picture of my home made blind on the car. As you can see, it helps to have a white car too! :D

[Brettster]

How on earth do you get those mpg's? Are you an elf? Best I've had so far is 46 mpg!!!

I try to drive in the blue in Eco mode as much as possible !

Do the 16" wheels make that much difference?

[Wass]

How on earth do you get those mpg's? Are you an elf? Best I've had so far is 46 mpg!!! I try to drive in the blue in Eco mode as much as possible ! Do the 16" wheels make that much difference?

There really isnt much of a secret behind those MPG figures. I am not an elf, I am an overweight 6'2" engineer.... ( nearly the same thing!) I stumbled upon th method of obtaining good fuel consumption more or less by accident.

My route on the 37.6 mile commute to work takes me along single carriageway A roads with lots of tractors, daft 20mph speed limits where they wouldnt be needed if they had just enforced the old 30mph limit properly, 40mph articulated lorries and hardly any straights in which to overtake. The result of all this is an hour long run into work with an average speed of...... you guessed it 37 or 38 mph. Sleepy Pete informs that the optimum operational speed for the hybrid system is 40-45 mph so, in other words I must be running in faily similar conditions to the original design brief specification for the vehicle. There are hills along my route, however, they seem to even each other out since I use more fuel to get to work ( because its colder in the morning and over the entire distance it is uphill) and I use less fuel to go home ( warmer and downhill overall).

You ask about the wheels/tyres:

I was given the option of those or the 17" and I chose the 16" options because they have a narrower foot print which gives better road holding in snow and wet roads ( this is why rally cars use narrower tyres in slippery conditions), they give less rolling resistance therefore use less fuel as you suggest, they help to soften the slightly choppy ride characteristic of the CT and the tyres cost a lot less to replace. The downside is that they dont look quite so good and I lose a bit of dry weather handling ability.

Another trick I learnt from the prius forum is to routinely check tyre pressures to ensure good economy.

[Sleepypete (FB)]

Sleepy Pete informs that the optimum operational speed for the hybrid system is 40-45 mph

Lol - caught me picking up info from other people

I'd concur with that 73mpg indicated though - I had that being registered on the trip computer after 20 miles of driving down the A46 at 40mph roadwork speeds. Frustrating driving but it shows that the potential is there for very high mpgs ... Just a shame my day to day trip takes me down to the 47mpg average on Fuelly :eerrrmm:

[Brettster]

Thanks for the info guys :)

I think the only way I'm going to improve my mpg is to loose my spare tyres

Shame I can't simply swap mine for a puncture repair kit lol