MPG Benefit after a service

Sidewayslarry

I decided to give the Vectra a service two weeks ago. We haven't got it long, and despite the car being due a service, I warned the dealer not to service the car because I knew his mechanic was absolutely useless and I knew they were putting in cheap 'Lotus' oil, so I said I would do it myself and know it was done right.

The car is a 2008 Opel Vectra, 1.6 Petrol. It has 105,000kms on the clock, and has been serviced in an Opel dealer since new and on the button.

I decided to ignore what the service book was telling me (that it was only due an oil service) and I bought a gallon of Castrol Magnatec, oil filter, air filter, 4 x NGK spark plugs, engine flush, and a fuel filter (rarely changed by main dealers unless requested)

That lot came to €110 which wasn't too bad for the amount of gear I got.

Completed the service in a little over 2 hours on a saturday morning two weeks ago.

Now the point of the thread is the following. In the two weeks that we owned the car before servicing it, €20 of petrol was getting us 180kms + - 5kms.
Since servicing the car, €20 of petrol is now getting us 200kms + - 5kms. Not bad considering she does very short trips Mon-Fri and then 60kms + per day on the weekend.

Before anyone suggests price differences at the pumps etc, I have all the petrol receipts here and we only buy petrol from one petrol station so it is pretty accurate.

A good service is well worth the money if the above is anything to go by.

biko

Aye, it's well known that a proper serviced car will repay you by getting better mpg. I think particularly the air filter impact on mpg is often overlooked.
Not to mention the satisfaction of being able to look after it.

fryup

Sidewayslarry wrote: »

I decided to ignore what the service book was telling me (that it was only due an oil service) and I bought a gallon of Castrol Magnatec, oil filter, air filter, 4 x NGK spark plugs, engine flush, and a fuel filter (rarely changed by main dealers unless requested)

are fuel filters difficult to get at?? where are they usually situated?

Sidewayslarry

fryup wrote: »

are fuel filters difficult to get at?? where are they usually situated?

They are handy to get to on the vectra anyway, just forward of the drivers side rear wheel underneath the car. Place a rag over the pipe so that the pressure release doesn't squirt petrol in your face

sebastianlieken

"engine flush"

Do you mind elaborating a bit on what engine flush you got and how you used it?

I'm in two minds about doing a flush before my next oil change. Any real benefit?

jimgoose

sebastianlieken wrote: »

"engine flush"

Do you mind elaborating a bit on what engine flush you got and how you used it?

I'm in two minds about doing a flush before my next oil change. Any real benefit?

I run a gallon of diesel through it. I generally do it with a car/bike of, shall we say, unknown provenance, and thereafter take the view that with regular, good-quality oil changes it isn't necessary. You can also buy specially-formulated flushing oils that are designed to allow the engine to run for a few minutes before dropping it out and replacing with regular oil.

vandriver

Maybe too soon to completely negate the possible placebo effect.Also,how do you know when the twenty quid is up?

Chimaera

The only true measure of fuel economy is to do a brim to brim measurement: fill the tank, record the odometer, empty it, record the odometer; the amount you need to refill it is how much you used to travel the recorded distance. Anything else is too prone to errors in measurement or judgement: like vandriver said, how do you know when you've used up the €20?

Also, never measure economy based on price: prices do vary, both between vendors, and in time even with the same vendor, and this introduces an error. If you have your receipts, and you think your judgement of the distance/fuel usage is on the ball, check the amount of fuel you bought and calculate your economy based on that.

Petrol seems to be currently around 1.49 €/l and lets assume that it was 0.01 €/l less 2 weeks before you serviced the car (not an unusual fluctuation).

So your first €20 would have gotten you 13.51 l of fuel @ 1.48 €/l. Covering 180 km on this results in a fuel economy calculation of 7.51 l/100 km.

Your second €20 would have gotten you 13.42 l of fuel @1.49 €/l. Covering 200 km on this results in a fuel economy calculation of 6.71 l/100 km.

So you're up. But let's factor in your error band of +/- 5 km. Worst case scenario, you might have 185 km before and 195 km after, with FE of 7.30 and 6.88. Still up but it's a smaller difference.

If your figures stand up, you've done well but by the sounds of it, the car had been poorly serviced up to this point. A well maintained car won't see such large gains from a service.

Sidewayslarry

My measure is far from scientific but there has been clear benefit since servicing the car in both mpg and in drivability and smoothness in the car.

I suspected poor servicing in the past which is why I used an engine flush. Cheap oil can leave a build up of sludge in the engine and in oil ways so this is why I generally flush an engine when doing my first service on a new addition to the fleet. The car had a main dealer full service history with it, but that is not to say that they used cheap oil when servicing it. The oil filter I removed certainly wasn't a genuine Opel part. The fact that this dealership has since closed down might suggest if they were cash strapped they may have used cheap oil also.

sebastianlieken

well the reason I'm interested in doing an engine flush is down to the fact that I have a 1.6FSI engine (timing chain).

this engine has an issue with the chain tensioner not working to it's full potential when the engine is cold as the tensioner doesn't fill with oil. (making the engine sound rattely and noisy for the first few mins) My thinking is that there could be sludge building up in that little loop where the tensioner routes the oil.

For the sake of 5 quid for some wynns engine flush, i can't really see the harm.

CJhaughey

Don't overlook the gearbox oil as well, its only a couple of litres on most cars and it is well worth buying good oil for that as well.