TDI mpg vs engine temp

[Cableguy]

No idea what make, just makes it go like stink

[lloydy]

We're they fitted by 'he who must not be named'?
And do you get any smoke on full throttle?

[Cableguy]

Yes and yes, but only a small amount

[HarryMann]

I have run another tank of fuel through mine now with the longer gearbox. probably 1/3rd motorway at 75-80mph, 1/3rd city, 1/3rd A roads and it returned 39.3mpg - still mighty impressed.

Are you doing your corrections correctly

Or should VW be taking notice and re-engineering their T5 vans

[jc_geddes]

its the same deal as last time brim to brim - I now have an app so I am starting to keep records of all fills, but it might be slow as its a toy and not an every day vehicle.

[jed the spread]

I swapped my stat for a new 87c stat today. Now sits 90-92c. The best bit is the heater now gets hot even when sitting in traffic.

I also noticed the MAF sensor housing has cracked where it goes fits onto the air filter. I filled it with silicon until I buy a new one. Jed, did you fit a genuine or aftermarket MAF? There is a huge difference in price.

I just bought a cheap ebay thing and it works fine.

Jed

[HarryMann]

Ah, Ok... slow helps a lot for sure.

I really meant have you adjusted for speedo, gearing and tyre-size calibration.

You would also expect winter fuel consumption to drop by between 5 & 8% seasonally c.f. a hot summer

[jc_geddes]

I will be collecting data slowly - rather then driving slowly, as I dont use it every day.

Correcting the speedo - its bang on at 62mph/100kph, but the out either side by a small amount. So how do I correct for that? but its odo we want isn't it?

The only thing to check is the odo is it over reading or under? but over a large distance to ensure the delta is understood say 100km what do we believe as the reference distance?

The data I am now collecting is odo (not trip) and brim to brim.

The tyres are std size.

[HarryMann]

Calibrating the odo against motorway marker boards over 10, 20 or 30 km, is not a bad way.

[clift_d]

Forgive me for asking what might seem like a really dum question, but am I correct in understanding that this 'refinement' only applies to newer 'replacement' engines, or is it something that I could also do with my OEM JX 1.6TDI?

[ewenmaclean]

Hello,

this thread is specifically for e-tdi engines - yours is not a tdi engine - it is a turbo diesel but not a direct injection head. The issue here is the amount of fuel tp be injected calculated by the ECU according to the values of the various sensors. The JX doesn't have many of these sensors or an ECU - it has a mechanical pump.

The general point about keeping the oil and water temperature in the correct operating range still applies, but to your advantage vw designed an engine for the van that was supposed to do that already!

Ewen

[clift_d]

Okay. That's what I thought might be the case. Thanks for clearing that up.

[HarryMann]

The general point about keeping the oil and water temperature in the correct operating range still applies, but to your advantage vw designed an engine for the van that was supposed to do that already!

Definitely Though you won't have any trouble with oil running too cold on a JX, virtually whatever oil-cooler you have. I've only once been tempted to baffle the rad, and that was deep, deep winter (-13C or so), but never did
I have though insulated some of the heater pipes and the return pipe from the rad... a bit radical, I know

[lloydy]

i have thought about insulating the heater hoses, a lot of heat loss there. Its pretty exposed under there though and i don't think anything will last long.
I've never quite understood the blocking the rad thing, especially on a rear engined van. Surely if the engine coolant stat is working, no hot water is going to the rad?
As the outside temp is dropping now, i am seeing that the engine takes that bit longer to warm up. But thats a general TDI thing

[HarryMann]

I've never quite understood the blocking the rad thing, especially on a rear engined van. Surely if the engine coolant stat is working, no hot water is going to the rad?

You would think so Lloyd. But in practice I'm sure you've found that dynamic systems are not quite that straightforward, esp. mechanical feedback systems are rarely totally open or closed loop, nor always as stable as we like to think. One thing that would spring to mind might be the relative sizes and flow-rates, once something becomes limiting, all bets are off. Or something unable to limit (quite enough )





I'll check & see if it's still there You may be right and it's all unravelled & stuck in someone's air intake up the M41

https://club8090.co.uk/wiki/Co ... ater_hoses explains that I was also rying to reduce the wikid (sic) heat through the cab floor (no mat nor gearlever boot at the time )