Can oil make THAT much difference to performance?

[Keydogg]

Hi,

the reason I ask this question is because if some of you remember my girlfriends 172 performs poorly for what it should. I estimate its around 20bhp down. Now, it was serviced just before she bought it, and now 12k miles later it needs another service obviously.

Now I was hoping it was so sluggish because the previous owner used s**t oil when servicing it, but would oil really make that much difference? I'm gonna put some decent fully synth stuff in but I'm really not that confident there will be any difference.

Any thoughts?

 

[daviebroon]

i'm not an expert, but give it a full on engine flush... use forte or something like that... then make sure you throw some slick50 and top grade oil at it.

using s**t oil would wear the internals in a way good oil won't. also depends how he drove it.

 

[Josh@Renparts]

its not going to make any obvious difference in the real world. and it definitely doesn't need any slick 50. Why do you think its down on Power?

 

[MikeB]

use a good engine flush and fuel injector flush should do the trick

 

[daviebroon]

why are you so certain that it DEFINATELY won't need slick50? for a start i never said it NEEDED it, however my experience over the years is very much in favour of it. Both in old and new engines. It greatly reduces wear, and can increase performance because it makes the oil work better creating less resistance in the engine.

 

[Chad]

why are you so certain that it DEFINATELY won't need slick50? for a start i never said it NEEDED it, however my experience over the years is very much in favour of it. Both in old and new engines. It greatly reduces wear, and can increase performance because it makes the oil work better creating less resistance in the engine.

I'm no expert but I'm sure there will be quite a few people that know a bit about engines that will tell you never to use slick50.

 

[Middo]

wont do any harm to use an engine flush, but its not needed if your doing an oil change and some good quality stuff is already in there.

i found oil made my car drive nicer, and experienced a nicer sounding engine on tickover. but it didnt make it any quicker.

 

[Josh@Renparts]

if slick 50 was so useful in new engines, oil companies would do a blend with it in. so he is down on performance, add slick 50 and you think that might cure it? its sure to be an underlying problem something which slick 50 isn't going to make any difference to.

 

[Jay Payne]

When i worked a Ford when we serviced the Transits we always used 15w40 grade oil as the other stuff we had was far too thin. Then we got hold of some 10w30 and the difference in engine performance was huge. I know im talking about 75hp diesel vans but thought it might help

 

[pinky]

When I sorted the oil in my car..good flush too..the note changed to a lovely purrr

 

[DAMO 40/172]

You just cant beat it!

 

[Fred@BTM]

if its had a cambelt change check for incorrect timing, very common

 

[brookes5117]

oil does make a huge difference on performance,i was running a car for a while and when i changed the oil the difference in acceleration was amazing,the correct and a decent make of oil reduces the friction in the engine parts helping to move more freely

 

[AmDaMan]

Don't use an engine flush, sometimes they dislodge very old hard gunk that eventally kills the oil pump and blocks oilways.

 

[brookes5117]

thats very true,and also been known to start burning oil for example cleans around the cylinders removing the build up of dirt leaving small gaps for oil to leak through,same for stem seals etc

 

[Keydogg]

When you say engine flush what do you mean? I thought you all meant run some bog standard crappy oil in it for a week to get the crap out then put good stuff in?

 

[MillerLight]

if the last owner was doing the servicing do you know if the spark plugs have been changed?

reno ones are about £70 i think and some good NKG are about 30.

last person may have put some crappy £3.99 set in.

just a though

 

[ForceIndia]

Heard of engine flush royally farking catalytic converters, all the crap they clear ends up there (I think)

 

[brookes5117]

an engine flush is something you buy from halfords etc,you pour it in your engine (not petrol tank) via the oil filler cap and run your engine for 15 mins or so and it removes all the crap from your internal engine parts

 

[SpaceMonkey]

I would use the best oil you can afford within reason.

I've used Silkolene Pro S on my last 3 cars & not had any issue.

 

[BRUN]

as above really, use good oil, a 5W-40 nothing thicker, Silkolene Pro S if you can afford it, its not cheap

the point about the plugs is a good one, they might need replacing, maybe they have been forgot about

dont put slick 50 in your engine, it can block oil filters, was a big court case in the U.S over it, do a google

if its run on crap fuel all the time aswell treat it to some V-Power for a few weeks help clean everything out, plus they were designed with super in mind so if your only running 95 then that wont help

 

[Keydogg]

if the last owner was doing the servicing do you know if the spark plugs have been changed?

reno ones are about £70 i think and some good NKG are about 30.

last person may have put some crappy £3.99 set in.

just a though

Good point. Well he was a mechanic for a renault dealer and he did it himself so I thought everything would be above board? Just spoke to my local garage who is very good and he's basically just said what you said, could be sparks, filters clogged, crappy oil all choking it to death.

The oil I shall be using is Torco SR1 fully synth 10w40.

 

[jph172]

I was always recommend to use fully synth like 10w 40/50 apparently it will run better i was told. But the sluggishness of the car imo dont neccesarily point to bad oil,it can be a number of things. Unfortunately some 172/182s are jus sh*t!
You hear all the time that someone has picked up a FAST 172/182 well it could jus be ragged so much that it jus dont like it.
Plugs would of been changed@the last service? or @least checked. Depends where you take the car, renault garages dont give the best servicing in my view unless it was serviced privately.

 

[franx]

do a search on oil

there was a thread one month ago by "the Oilman" which told everything needed to know