The AX Eco Project : 100 mpg target !

[renault_megane_dci]

Top notch oil is what took my Clio 1,9D from 700 kms tank to 800 kms tanks back in the days.
It also made the car much smoother.

[HypermilerAX]

Originally Posted by renault_megane_dci

Top notch oil is what took my Clio 1,9D from 700 kms tank to 800 kms tanks back in the days.
It also made the car much smoother.

I don't believe one second oil change can improve efficiency by 14%. There must have been other things that made you go further. But thanks for your feedback.

[euromodder]

Originally Posted by HypermilerAX

I already considered less viscous oil but I don't think the tiny gain will pay the higher cost of the oil.

It doesn't have to be much more expensive.
It is when you buy from the big brand names.
But you really don't need to do so ...

Dunno if you can read a bit German ?
14 Motoröle im Test: Wie gut ist Billig-Öl? - AUTO MOTOR UND SPORT

How good are cheap oils ...
Turns out most of the cheap stuff is just about as good as the expensive oil .
The reference in the test is Castrol oil to VW 507.00 spec.
Good stuff, but expensive @ 22 €/L

You can read the oil names

Urteil = test opinion or result
Empfehlenswert = recommended
Bedingt empfehlenswert = less recommended


Some manufacturers also state their products are OEM approved under a different name ... and with lots of companies being owned by the same mother company I'm not surprised about that.
BP own Castrol and Aral.
They've done high-low market split well before Renault - Dacia.

Similar applies to tyres, BTW , with high-end OEM wanting a share of the cheap market as well.


Dunno about buying oil in France, but the Germans have some web shops that sell oils at far lower prices than what we'd pay here in Belgium ...

I think I can go as low as 5W40 but to see real improvements the second index should be lower as my oil temp is at operating temp 85% of the driving time. So changing from 15 to 5 will affect efficiency only during 15% of the driving time.

The advantage of the lower cold weight oils, is that they lube better when cold - while the higher cold weight oils are still too viscous to properly lube.

Back in the day when cars requiring say 15w40 were built, the low (cold) viscosity oils with weren't about or were very expensive and viscosity modifiers weren't nearly as sophisticated or effective.

I won't mind going for lower viscosity on the cold end with a modern oil, but I wouldn't go lower than the lowest spec the engine manufacturer prescribes on the hot end.
That's the weight of oil the manufacturer thinks his engine needs to keep it properly lubed. If the oil is too thin when warm, it won't properly lube anymore.

If PSA allowed .w30 weight in the 1.5D, I'd run it.
If they only allowed .w40 weight, I'd stick to that.

Originally Posted by renault_megane_dci

Top notch oil is what took my Clio 1,9D from 700 kms tank to 800 kms tanks back in the days.
It also made the car much smoother.

What do you call "top notch oil" ?
Best quality, or some lower weight oil ?

[renault_megane_dci]

Originally Posted by HypermilerAX

I don't believe one second oil change can improve efficiency by 14%. There must have been other things that made you go further. But thanks for your feedback.

That and me starting to pay attention to my driving, the car didn't get any mods, not even over inflated tires.

And said driving was fast-ish (it was back in 2002 to 2007) more at posted 70 mph than the 55 I am using these days ...

4,9 liter / 100 kms has been my personnal best with this car (very far from an AX performance, but not too bad either given I didn't try too hard)

[renault_megane_dci]

Originally Posted by euromodder

What do you call "top notch oil" ?
Best quality, or some lower weight oil ?

Synthetic oil, 5W30 instead of 10W40, I think I bought a supermarket oil though ...
The maintenance plan was quite short @ 10K but I recall the difference didn't appear straight after the oil change but rather over time.
The engine got much smoother, allowing for a ride in 5th when it would have begged for 4th before.

[JRMichler]

Once upon a time, I changed the oil in a CB350 Honda motorcycle to Mobil 1 synthetic. Mileage increased from 87 MPG up to 103 MPG at 30 MPH and 60 MPG up to 63 MPG at 60 MPH, with similar improvements at 40 and 50 MPH. At first I thought I was on to something, then I realized that I had got better at holding the throttle constant.

Key conclusions: The carbureted 350 Honda really responds to DWL. And ABA testing is important. And getting better at DWL allows running in top gear at lower speeds.

[HypermilerAX]

Originally Posted by euromodder

It doesn't have to be much more expensive.
It is when you buy from the big brand names.
But you really don't need to do so ...

Dunno if you can read a bit German ?
14 Motoröle im Test: Wie gut ist Billig-Öl? - AUTO MOTOR UND SPORT

Thanks for the article, German happens to be my second mother tongue.

Originally Posted by euromodder

If PSA allowed .w30 weight in the 1.5D, I'd run it.
If they only allowed .w40 weight, I'd stick to that.

Only 5/10/15 W40 is OK for the 1.5D. I can try out 5W40 this winter. So yeah, no W30 in the TUD5. My engine has now 317.000 km (corrected) and I hope to keep it at least until 500.000 km.

Originally Posted by renault_megane_dci

And said driving was fast-ish (it was back in 2002 to 2007) more at posted 70 mph than the 55 I am using these days ...

That was before. In the 80's my father often drove 100 mph in 70 mph zones, now it's more 45-50 mph.

Originally Posted by JRMichler

Key conclusions: The carbureted 350 Honda really responds to DWL. And ABA testing is important. And getting better at DWL allows running in top gear at lower speeds.

Interesting, thanks.

[euromodder]

Originally Posted by HypermilerAX

Thanks for the article, German happens to be my second mother tongue.

OK, then you'll understand it better than I do

Only 5/10/15 W40 is OK for the 1.5D. I can try out 5W40 this winter.

I've seen 5w40 for under 4 euro/L (+ shipping)

Even Total Oil which goes for far more over here ...

BTW :
In Germany, they can apparently only sell fully synthetic oil / synthetisches Öl labeled as such.

Any added marketing lingo like "Synthesetechnologie" means it's not a fully synthetic oil

[HypermilerAX]

For those who missed it, here is my high speed test :
http://ecomodder.com/forum/showthrea...mph-27313.html

Forgot to mention it, I installed a throttle block at the end of the cable. It prevents me to go further then about 80% load. I hope it helps during acceleration phases and P&G.

Today, I made some coastdown tests. The conditions were good, almost no wind. Flat, dual lane road. Paid attention not to be in a vehicle's wake.
Temp : 17°C
Humidity : 95%
Pressure : 1020 hPa
Air density : 1,233

For the Cd, I coasted from 110 to 80 km/h, I recorded the whole test on GPS and calculated out of the excel sheet. About 10 coastdowns were made in each direction. Each direction has about the same values, meaning that there's is no grade and no wind. On average, the car needed 21,207 seconds to coast from 110 to 80 km/h.
For the Cr, I coasted from 17,1 km/h to a complete stop. 5 runs in each direction gave 65,74 seconds average.

The results are :
Cd : 0,395 (with A = 1,696 m²)
Cr : 0,0071

Thoughts :
The Cd seems very high. The car official's Cd is 0.31, I can understand that the value is optimistic but to get as high as 0.395... And my car is even aeromodded... I don't think my tests have any inconsistencies. I'll take the value as it is. The good news is that my engine has one hell of an efficiency with a 0,67 CdA. About 230 g/kWh at 2900 rpm and 80% load.

The Cr seems too good. It is very hard to match the segments in each direction : if I accelerate too much, I end up coasting a bit further (be it 10 m) and very small gradients can alter the test. I cannot say that the average gradient of "E direction" = average gradient of "W direction".
Other explanation : accuracy of initial speed. I drove at 20 speedo for a while and took the GPS average. The problem is that the counter seems to have some inertia at these low speeds, it only moves for a noticeable speed change but not very small changes that the GPS sees. My GPS average was 17.1 km/h and I started the time counter when the needle passed 20 km/h. But I'm not 100% sure the speed is 17.1 km/h.

I hade made 2 other tests, not exactly at the same place but flat and same road quality:
Michelin Energy at 2.2 bar : 0,0109
Michelin Energy at 3.0 bar : 0,0095
Yokohama Bluearth 3.5 bar on front + Energy 3.0 bar on rear : 0,0071

That would mean that Yokohama's allover at 3.5 bar would have 0,0047... not possible.

Starting from a stop and roll down some very light decline might be more precise.

[euromodder]

Ha, the luxuries of a mechanical gas cable