I know what the general view is, drive straight off. But, I've been thinking about this for a some time. Surely, wear is caused by friction between moving surfaces (even when there is an oil film present), and obviously the tighter tolerences present when cold will accelerate wear. However, surely it is the number of revolutions in an engine that determines the actual wear (ie not really related to time running). So, if an engine is allowed to warm up it takes a certain number of revolution for it to reach normal operating temperature. It will take less revolutions to do this at idle simply because there is no airflow through the engine bay to cool it, it relies purely on the water jacket. Whereas it will take more revolutions when driving as there is now additional cooling in the form of airflow. It might take longer in time to warm up at idle, but less revolutions of the engine. You can see where I'm going with this, the engine suffers less wear if allowed to warm up at idle. Discuss.

All of that said, I drive straight off because I'm going somwhere and can't be bothered to spend a disproportionate time waiting for the engine to warm up before setting off. It's just something I've given some thought to. One of my other subjects is whether axle wind up is a myth. Drives:
2010 FFRR TdV8 Vogue - Stornoway Grey
2010 FFRR TdV8 Vogue SE - Zermatt Silver
1998 BMW E36 M3 GTII

i let mine idle for 15 secs or so while i put my seatbelt on and check things like mirrors , climate etc...

i have no tech proof that this helps the engine though.. ... - .- -.




Y. O. L. O.
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+1 Stan, by the time you figure out what radio station to listen to it's time to go.
On top of warming up, always allow the turbo to cool down slightly, even just 5-10 seconds at the end of a run helps. 2012 Orkney Grey Westminster 4.4TDV8 with Ivory interior.........nice!
Alfa Romeo Giulietta
Just one Montesa now, 349 White Wonder
Austin A40 Farina MK2
1975 Morris Marina 1.8TC

As you say, the general view is to just drive straight off, although as Stan quite rightly points out, there is generally a delay whilst you get settled and ready to start your journey. The 4.4 TDV8 doesn't need much effort to move down the road so I tend to just take it easy and don't race down the road trying to get up to speed as fast as possible. There's not a huge difference in rev's between idle and doing 30MPH so wear would be a minimum I'd guess. Although I have to say I have never known a vehicle with such a delicate DPF system. 2011 TDV8 Vogue SE

I start. Check that there are no bongs or messages. Seatbelt on and then a very gentle drive until the engine temperature is rising and close to normal.

Jim

I'm struggling to answer this.....on large marine engines, we have pre-lube pumps and jacket water heaters. For example the v16 Caterpillars in the boat I work on at the moment are kept at a steady 40 degrees Celsius and have a pre-lube pump that runs for about 1.5 minutes until the oil pressure in the engine is around 0.5 bar (7.5psi). This is to allow a good oil film to prevent wear on start up. The pre-heat is to keep the tolerances as they should be, so that the engine can be used without idling for too long.

On a small vehicle engine, albeit a large v8 for a vehicle engine, as long as you have let the engine idle for a minute or so, then don't boot it straight away, all should be fine. The most wear in an engine is considered to be done at start up. Without the ability to pre-lube vehicle engines, idling for a minute or so would be fine.

The warming up of an engine to running temperature is important, but in my opinion that is only to prevent issues at full load. As long as you have oil pressure after start and oil pressure once warm, all "should" be ok.

A bit of a waffley response but thats my 10 pence worth. Basically, start up, allow to idle for a minute or so to allow oil to get round the engine, don't boot it till warm.

Cooldown is equally important. Don't just stop, switch off, get out. Its best again to let the engine run on for a minute or so. This allows the engine to settle and the turbos to be oiled and therefore cooled. Any residual heat from full load running can be dissipated and that is only a good thing for an engine.

Ben

rvbush wrote:

Surely, wear is caused by friction between moving surfaces (even when there is an oil film present), and obviously the tighter tolerences present when cold will accelerate wear.

I agree with all above. I tend to wait until the idle drops, then drive off slowly & don't give it any beans until the engine is up to temperature.

Totally agree with the cooling down of turbo engines (I think failure to observe has seen the early demise of many turbos). I'm lucky, the last minute or so of my journey home is on nice level roads where it's not safe to exceed 20mph, which lets everything cool off nicely. Also agree with letting an engine get properly up to temp before using the performance. I've got an old BMW M3 and the manual is very specific about not using more than 4000rpm until the engine oil temp (they have a gauge) reaches at least 80 Deg C, I tend to keep below 3000rpm until it's nicely up to 90Deg C. Drives:
2010 FFRR TdV8 Vogue - Stornoway Grey
2010 FFRR TdV8 Vogue SE - Zermatt Silver
1998 BMW E36 M3 GTII

I'm a bit "old school" in as much as letting the engine idle whilst you settle in, then driving off gently & keeping the revs down until its fully warm.
Also, I let the turbo cool down & stay lubricated before shutting down.

Modern lubricants are probably better at staying on bearing surfaces than those of long ago. However, old habits die hard & it cannot do any harm.

Oddly enough, I had a telling off from a driver trainer yesterday for being "old school"**. I made my opinion clear but at the end of the day it's their engines & turbos that will have shorter service lives in return for a few drops of diesel saved.
& yet I can achieve around 15mpg in a fully loaded 18T truck (engine driving the fridge too) 50/50 motorway/London traffic !

** Absolutely everything we do driving a HGV thesedays is monitored & logged, not just roadspeed, braking, gear changes, engine RPM's, cornering forces & probably what radio stations we listen too - go slightly out of any of their pre-set parameters & it is recorded. IMHO, the driver should be concentrating on road conditions not the admonishing voice from the tablet and the subsequent interview with a driver trainer who spends too much time driving a desk & looking a graphs.

Sorry, I've wandered off topic but I needed a rant this morning. 2003 Range Rover Vogue TD6

Funny you say this Brian. An HGV driver friend of mine has just had exactly the same rant. He is like us, warm up/ cool downs. If you look after your vehicle it will look after you mentality. The clowns that run things who have never done the job are the problem. Anyway......we've digressed.

Your quite right, especially on a larger heavy duty HGV engine. Although modern lubricants can do a very good job, we still look after them in the Marin industry. Changing 1000 litres of engine oil every 1000 hours of use gets expensive if you have to start doing it more frequently due to poor engine management.

It is my belief that light vehicle engines are designed with the average Joe in mind so maybe we are overt thinking all of this. The exception is engines like those in rvbush's M3 which have certain design parameters built in as a result of extracting all possible performance out of that particular type.

A large lazy v8 in a Range Rover if treated well shouldn't ever suffer anything other than normal wear and tear. Without regular lube oil sampling it is very hard to tell what that may be though.

Last edited by btiratsoo on 9th Jun 2020 2:42pm. Edited 1 time in total

I think it's mainly turbos that suffer in this extended oil change, no warm up/cool down age. Turbos run hot, it makes sense to let them warm through before expecting 90k rpm (or whatever) and then to let them cool off with oil flowing through them (also acting as a coolant) before shutting off and to change oil/filter at half the manufacturers advised periods. Drives:
2010 FFRR TdV8 Vogue - Stornoway Grey
2010 FFRR TdV8 Vogue SE - Zermatt Silver
1998 BMW E36 M3 GTII

It doesn't take much to wreck a turbo! You're quite right there rvbush, warm up/ cool down is critical for turbos and regular oil changes. Think of the tolerances in the shaft and bearings of a small turbo on a TDV8. Its a failure point.

Mine idles while I go and shut the garage door/load anything in to the boot, and then there are several miles of 20mph limit before any higher revs. The reverse on return. I do believe in not booting engines before they have warmed up. This is reinforced by some BMW motorcycles which have TFT screen instruments: when the engine is cold the red line is at much lower revs on the virtual rev counter, it then moves up to the standard level once the engine is warm enough. A good idea that could be more widely adopted. Only Range Rovers since 1988

I just get in and drive off slowly and I also arrive home slowly 20mph on my housing estate. I was just wondering if any turbos will be spinning anyway. Geoff