Forum menu
Cut down on the short journeys ( These are a killer on MPG - I have the same engine as you ) and walk or cycle these journeys instead.
No, car purchase at height of market so will take hit on p. Ex.
Car is loved and ticks the boxes
Why is buying a different car not an option?
1. I was forced to buy a car at pretty much the high point of the second hand boom so I suspect I’d take a real bath if I sold it.
2. I’m not comfortable selling a car with a potential fault. I know, stupid, right?
3. I really like the car. Getting low-mid 40’s on a long steady run was a bit of a shock after the easy 50 of the 2L 5 series on similar journeys but the grin factor when I hoof it and the phwoar factor when I look at it is worth it.
Cut down on the short journeys ( These are a killer on MPG – I have the same engine as you ) and walk or cycle these journeys instead.
That's not bad advice in general, but I'm not including short journeys in my comparisons.
Last night I had to drive to Stratford, twice. For the second journey I zeroed the trip on departure and the temp gauge was showing normal temps in under a mile. That trip, late at night so fairly little traffic returned 36.7mpg and I drove it as gently as possible; coasting down to changing speed restrictions but using the cruise control to accelerate when the opportunity arose. The car can display a minute by minute bar graph and I saw 60+mpg on occasion but also sub 15 in places. Unfortunately, turning off the engine clears the screen so I have no record of it.
temp gauge was showing normal temps in under a mile.
That's water temp..... It's oil temp that shows the engine state.
36-37 sounds OK for that size engine.
I'm just about to do a 110 mile trip (65% dual carriageway and 35% decent A road.
Two up plus 2 dogs and a load of stuff in a 3L V6 big thing with wide tyres.
I'll be fairly happy if I get 36-37 for this trip.
Car doesn't display oil temp. I've ordered an OBD reader so hopefully that'll be a parameter I can see.
1) The state of the market affects buy and sell equally. That's a non-issue.
2) Correct, it's stupid. 😁 "Buyer beware" applies to private sale of second-hand cars and utterly irrelevant if you hoisted it to a dealer. And in any case, you don't actually know that there's a fault or this thread wouldn't exist. If you didn't have a prior baseline so the mpg wasn't lower than it used to be, would you suspect a fault at all?
3) You really like it apart from the perceived poor mpg (and mid 40s ain't bad, I'd be happy with that out of our 1L Seat). And be honest, if you're getting a grin factor from hoofing it then mpg isn't your primary concern now, is it.
So buying a different car is an option, you just don't want to and are making excuses.
Do you need all that haulage space on a daily driver?
and mid 40s ain’t bad, I’d be happy with that out of our 1L Seat
Yep, I can't get better than 45mpg average on our 1L Fiesta Ecoboost.
I took it on the same 110 mile trip I've just put up there and struggled to do 50mpg overall.... It was painful.
+1 that our older 1.4 16v Ibiza struggles to get above 45mpg on a run, less with a load on board.
36-37 sounds OK for that size engine.
You're missing the fact his MPG suddenly dropped. And all the other people saying that their cars with the same engine also did better.
3) You really like it apart from the perceived poor mpg (mid 40s ain’t bad). And honestly, if you’re getting a grin factor from hoofing it then mpg isn’t your primary concern now, is it.
If I was still getting mid 40s this thread wouldn't exist and hoofing it has taken a definite back seat since the service.
1) The state of the market affects buy and sell equally. That’s a non-issue.
I respectfully disagree.
I suspect the car is worth about £9K on the forecourt, so that's, what, £7-7500 in PX? As I don't have money to add to the pot, I'd be trading down quite significantly. The cheapest 2.1L CLS on Autotrader is over £9K. I know I don't have to have another CLS before anyone points that out, but it's my money and I'll spend it how I want.
This thread was never about the cost, it's about my concern that there is something wrong with my car.
Did you check MAF plugs? If they're plugged in you could try unplugging them for a bit.
Assume you have two?
Found a fair few threads on this. On this one there's an interesting one:
Usually disconnecting the MAF(s) is a way to determine if its working. If rpm’s rise when disconnected then it suggests the MAF(s) is functioning. No change means the opposite.
On my OM642 which has twin MAFs, one failed and my consumption increased greatly. No obvious change in drivability, no undo smoke, but it sucked fuel hard.
MAFs can fail completely or they can just give poor readings. I noticed my Passat (without DPF) was smoking. slightly - new MAF fixed it. But don't get cheap MAFs (or any sensors) since whilst they might work the readings might be inaccurate.
Yes, twin mafs on the batwing.
Iirc £750 stealership prices then around half for arftermarket.
Surely the car would tell you tjere was an error amd throw a cel.
If the reported MAF value is just inaccurate, it won't throw a code. Only if it's getting no reading at all or sometimes something wildly implausible. There are several types - one is a heated wire whose temperature is measured - more air flow cools the wire more. That type is affected by getting dirty of course.
This guy's car is petrol but some interesting ideas on this thread.
This thread was never about the cost, it’s about my concern that there is something wrong with my car.
Go back to the garage with your findings and ask for an explanation, then. If there -is- something wrong with your car that wasn't present before it had its service then it's their problem not yours, and what you have here is four pages of guesswork from people who have never seen it.
If I were to join in the guessing game then out of everything presented here, the new tyres sounds most plausible explanation. I am not a mechanic.
From my first post…
but I can’t return to the garage for reasons that aren’t worth wasting many pages on, so don’t bother asking…
Apologies, I forgot that bit.
If it’s twin MAFs Car Scanner will give you figures from both so if they are vastly different that could indicate one faulty.
My scanner arrived this evening so I'll have a play over the next few days.
You’re missing the fact his MPG suddenly dropped. And all the other people saying that their cars with the same engine also did better.
No I'm not because the OP said that the car used to do mid-high 30s (when he bought it when it was warmer) and then it was doing low 30s (over the winter).
He's just done a run at nearly 37 which is getting back towards to what it was.
It's extremely difficult to compare FC with other people as there are so many variables.
On my 110 mile trip yesterday I was getting a reported 38mpg on the dual carriageway with the cruise control set at 73.
Once I got into the A roads it dropped to 36 purely due to some junctions.
The type of road makes a massive difference as it's the acceleration that kills the FC figures.
You will get worse economy with cruise control than using a very light foot
Not in my experience.
I would say its very much terrain and speed related.
If its flat at a steady cruise of say 58 to 65mph, cruise is probably almost identical.
If ot gets hilly amd you wanna go a wee bit quicker, then driving the car and letting speed bleed by say 10mph on the steeper sevtions then using the downslope to regain momentum, probably manual use of the loud pedal wins
This is something that is coming, smart cruise. Linked to route calculation, traffic and road profile. Needless to say, it's really ****ing complicated...
If ot gets hilly amd you wanna go a wee bit quicker, then driving the car and letting speed bleed by say 10mph on the steeper sevtions then using the downslope to regain momentum, probably manual use of the loud pedal wins
I do this regularly, particularly on the drive through Europe. Works a treat.
If ot gets hilly amd you wanna go a wee bit quicker, then driving the car and letting speed bleed by say 10mph on the steeper sevtions then using the downslope to regain momentum, probably manual use of the loud pedal wins
I do this regularly, particularly on the drive through Europe. Works a treat.
This is a big one!
It can be surprising (well, not any more once you know) how hard the car is accelerating up steep or long climbs when you knock cruise off, and realise you have to push the gas really hard to maintain what cruise control was doing. Thus scrubbing 10-15mph means a lot less throttle in those situations. And naturally the other side you can just roll back up to whatever pace you were going with minimal throttle
Not in my experience.
Years ago Jeremy Clarkson attempted a trip from London to Glasgow on a single tank of fuel.
He found that cruise control is more thirsty overall if you want to save fuel.
When I press resume on my car it accelerates at a "non-efficient" rate compared to manual acceleration.
Years ago Jeremy Clarkson attempted a trip from London to Glasgow on a single tank of fuel.
Was Lands End to John O'Groats wasn't it?
When I press resume on my car it accelerates at a “non-efficient” rate compared to manual acceleration.
Do you use eco mode? I know mine is marginally better but not by much, sometimes I wonder if it's just designed to make you think it's more economical by reacting slower.
Was Lands End to John O’Groats wasn’t it?
No, it was London to Edinburgh and back on one tank
Do you use eco mode?
Umm no it's a Porsche.... It doesn't understand "eco" 😬
No, it was London to Edinburgh and back on one tank
Ahhh.
I think it rather depends on the car. The most efficient trips I have done in the Merc by a significant margin involve the A34 south from Newbury. This is a dual carriageway with lots of fairly sharp hills that need quite a bit of throttle. I do this with the cruise control on. In this car it seems that it's more efficient at higher loads than other cars I've had, but it still coasts down the other side of the hills.
In some cars, a tiny bit of acceleration causes the instant MPG to plummet. So when it's not particularly hilly, the slight acceleration and deceleration you end up doing when not using cruise cost you fuel. The Prius was particularly sensitive to this. In my experience in that car, using cruise was more efficient than not unless it was particularly hilly. A38 in Cornwall for example, the car was thrashing itself on those hills at 70mph which clearly wasn't effective. That's where mert's intelligent crusie would have come in handy because the car would have been able to use battery power to get up the hills knowing it would be able to recharge coming down.
Of course, if you are letting your speed drop on hills you are going slower overall, which would have a significant effect in itself.
Of course, if you are letting your speed drop on hills you are going slower overall, which would have a significant effect in itself.
Not hugely, most of your issues around journey time (especially in europe) is the getting to and from the main/arterial roads.
Slowing from 70 to 60 on a mile incline will make so little difference to total journey time, it's all but irrelevant. Masked by a bad traffic light cycle or a pelican crossing. (Though dropping speeds generally makes a massive difference to FE, just reducing mine by 5kph gained me about 5%.)
The precharging of the electric drive system in a hybrid before inclines/recharge on descent (and using electric power to change speed) is already in a few cars on the market.
Anyway. I tested my car with the MAF disconnected and it went straight into limp mode.
My MAFs don't read the same according to the app the @colp suggested, but I don't know what variance is acceptable. Or if it a MAF issue or an air filter issue.
That's a bit of a giveaway. What percentage are they out?
MAF A is reading approx 15.5-16 kg/hr and MAF B is reading approx 11-11.5. So a lot.
That's definitely wrong. There's no way that's within normal range. Good thing you have two to compare with each other! You don't need to know which one is wrong - buy one MAF, measure the new one, and whichever doesn't agree is the problem unit.
Not sure about your engine but mine is sat on the top and should be a 5 min job with a screwdriver.
Buy a decent brand though. They aren't cheap, but neither is diesel or a DPF. It's worth giving Merc a ring as they aren't always a rip-off, and you're guaranteed quality. Sometimes aftermarket ones aren't as good, even with the same brand.
Get a Berlingo 😀
Its called the batwing and it contains both mafs. You change both at the same time.
I changed my air filters yesterday, what a faff. You have to remove the cold air feed, then drop the airbox off the batwing, remove from car, then swap them over. Full of leaves and black from road grime
Service book states changed 11,000 miles ago. I think not.
The next question is what does the ecu do with the maf readings? Average them out would be my guess as the air is combined into the turbo downstream of the mafs anyway. But if you have 1 maf at plus 40% then your potentially overfuelling by 20%
Shame your s o far from me, its an easy swap to see what a different batwing shows
There's only one turbo??
Re filters, on mine apparently the fuel and air filters are on a different schedule to the normal service, every 45k apparently. So it's easy to miss them if you are not always using the same garage.
Haven't read it all but aware you have a very thirsty engine...however, check the brakes aren't sticking...I've just replace a caliper, disc and pads and I'm not back to over twice the mpg.
On the om642 3.0td mb engine in my car, yes 1 x turbo. 224 bhp version.