question about engine speeds

[rich_g85]

is there any difference between holding the accelerator down (engine in neutral) to about 3500RPM for a couple of hours and cruising on the motorway for several hours in 5th gear at around 3500rpm?

also, say youre at 80 on the motorway (i know you wouldnt but just say you are ), what speed is your engine doing (in RPM)

just curious, cheers

 

[Djw John]

Yes in the first one you you travel a lot further if its in gear!

At 80mph I think its about 3750rpm in my 1.4 2000

 

[rich_g85]

Quote: Originally posted by EvilJohn on 16 March 2004


Yes in the first one you you travel a lot further if its in gear!

At 80mph I think its about 3750rpm in my 1.4 2000

LOL, i meant engine wear and so on, as it seems horrible revving the crap out of it in neutral, although you seem to do the same thing on the motorway and i have no qualms about that!!

 

[JAY172]

the rpm is the same but the throttle position and engine load isnt.if in nuetral the engine isnt under load so will req only a slight bit of throttle to hold it at 3500 rpm.but whilst your moving you need more throttle due to the engine being under load.you need more throttle to stay at 3500rpm because the engines got to move the weight of the vehicle etc(under load) as well as stay at 3500rpm.the revs at 80mph depends on the ratio of the gear your in.different models use different ratios so the revs will be slightly different.

 

[cliosportcraig]

On the motorway there is going to be a lot of wind @ 80 MPH which cools down your rad etc !! If you sit on your drive @ 3500 RPM the car will over heat !!

 

[rich_g85]

off topic for a second, Jay ive been reading a few of your posts recently and you really seem to know what youre talking about, do you work for Renault or somebody similar??

 

[JAY172]

im an rte at a renault main dealer mate.posting on here at night stops me going to the pub and regreting it the next day.i need sky.

 

[rich_g85]

ok cool, heres a quick one for ya then, do you know what oil they tend to use in the engine and the gearbox when my car goes for a service at a renault dealer? out of sheer idle curiosity!

 

[JAY172]

depends on dealer ive found.we use 10/40 semi synthetic(unsure of the make though).gear oil is esso trx 85/90.gearboxes are filled for life so it shouldnt need changing unless a repair reqs them to drain it(clutch,driveshaft etc)

 

[rich_g85]

i know im way off topic here but hey its my topic!!

my gearbox is getting old (118000 miles), and seems to be becoming a little notchy, and never goes into reverse first time any more although asking them to put in new gear oil made a slight difference..... also changing down the gears especially 3rd to 2nd you need to give the stick a bit of a pull into 2nd gear.

if these things are sealed for life as you say, i take it there is nothing else you can do apart from new gear oil to help things along? (short of a new box!!) one techie i spoke to suggested the clutch may not be disengaging totally??? clutch pedal seems very stiff, engages almost like a switch-caught many people unawares resulting in a stall!!!

right that is my last question, now im going to bed!!
thanks all.

 

[JAY172]

i meant sealed for life as in the oil doesnt need changing.you can still strip them and change synchro rings etc.a clutch fault would affect reverse selection as reverse has no synchros so the clutch must fully disengage otherwise you will have difficulty selecting reverse.you could try some fresh oil but it sounds like the clutch may be the problem.

 

[rich_g85]

excellent, thank you for your advice. i hope you dont mind me picking your brains! ive got loads of questions but im completely knackered now, gotta be up at 7!

thanks again

 

[JAY172]

same here off to bed i think.