A quick question please. Does anyone know whether any of the Fiesta MK8 Mild Hybrid MHEV have a wet belt engine or do they all have a timing chain ? The car I'm seeing is year 2020. Maybe I should also ask anyone who has that engine whether they are pleased with it or not. It's the 125 HP engine. Thank you 🙂

1.0 EcoBoost MHEV are all chain driven.

I don't think you'll want my opinion on them.  

Chain drive but the oil pump is wet belt. 

10 minutes ago, TomsFocus said:

1.0 EcoBoost MHEV are all chain driven.

I don't think you'll want my opinion on them.  

Actually I would value your opinion 😉

 

6 hours ago, Matt Alsop said:

Actually I would value your opinion

Well I'll stick my 2 cents in. In my opinion the 1.0 Ecoboost with the wet timing belt is something to be avoided at all costs.

The newer 1.0 Ecoboost with the timing chain hasn't be around long enough for there to be any meaning full track record of reliance. It will be another 3 or 4 years before it will be possible to start and form an opinion on the reliance of the Ecoboost MHEV. Just remember the vehicle is not a hybrid, it simply uses the electric to boost the torque when accelerating.

1 hour ago, Matt Alsop said:

Actually I would value your opinion 😉

Performance on the MHEV is great.  I had the 155ps version in the heavy Mk4 Focus (Active Vignale) and didn't miss diesel at all.  (Totally different experience to the non-MHEV 1.0 125ps Mk3 Focus I had before).

Economy was decent considering it's a petrol, 155bhp, and a heavy car.  Averaged 45mpg over the same roads that my 2.0 TDI 140 does 55mpg.

But refinement is where the MHEV is really lacking.  Very loud, very rough, just all round unpleasant with strong vibrations at idle and a horrible rattle while cruising even at 30mph.  People on here often complain about the engine cutting out at standstill, but that was my favourite part, finally some relief from all the noise and vibration!

I also hated the regenerative braking.  Obviously that's going to be part of any hybrid or EV, but I just don't think the mapping works well on these at all, trying to balance a manual petrol engine and regen braking makes town driving very jerky, and totally spoiled the drive for me.  When you lift off throttle or cancel the cruise control to roll up to a junction, the regen braking suddenly, but unpredictably, jolts the car within a few milliseconds. 

I've sold mine and gone back to a 'conventional' engine, with no electric assistance.  I am much more sensitive to things like noise & vibration than most people, so I would urge you to test drive one, rather than relying on anyone else's opinion.

Regarding reliability, I do believe these will generally be more reliable than the wetbelt version.  Ultimately there's a lot less rubber to clog the oil pump if the small belt degrades.  And you should get warning signs (oil pressure light or EML with VCT warnings) where the engine could still be saved with just a new oil pump belt.  It's also worth noting that the oil pump belt has a recommended replacement interval of 144k or 10 years.

26 minutes ago, TomsFocus said:

Performance on the MHEV is great.  I had the 155ps version in the heavy Mk4 Focus (Active Vignale) and didn't miss diesel at all.  (Totally different experience to the non-MHEV 1.0 125ps Mk3 Focus I had before).

Economy was decent considering it's a petrol, 155bhp, and a heavy car.  Averaged 45mpg over the same roads that my 2.0 TDI 140 does 55mpg.

But refinement is where the MHEV is really lacking.  Very loud, very rough, just all round unpleasant with strong vibrations at idle and a horrible rattle while cruising even at 30mph.  People on here often complain about the engine cutting out at standstill, but that was my favourite part, finally some relief from all the noise and vibration!

I also hated the regenerative braking.  Obviously that's going to be part of any hybrid or EV, but I just don't think the mapping works well on these at all, trying to balance a manual petrol engine and regen braking makes town driving very jerky, and totally spoiled the drive for me.  When you lift off throttle or cancel the cruise control to roll up to a junction, the regen braking suddenly, but unpredictably, jolts the car within a few milliseconds. 

I've sold mine and gone back to a 'conventional' engine, with no electric assistance.  I am much more sensitive to things like noise & vibration than most people, so I would urge you to test drive one, rather than relying on anyone else's opinion.

Regarding reliability, I do believe these will generally be more reliable than the wetbelt version.  Ultimately there's a lot less rubber to clog the oil pump if the small belt degrades.  And you should get warning signs (oil pressure light or EML with VCT warnings) where the engine could still be saved with just a new oil pump belt.  It's also worth noting that the oil pump belt has a recommended replacement interval of 144k or 10 years.

Thank you so much for the detailed description. I did wonder what happens when you lift off the throttle on an MHEV car. I've not been to see it today as I've ended up to busy. I will look at one sometime very soon and certainly drive it so I know what to expect should I later buy one or something similar. To be honest I'm only really looking as I have a Red Edition 140 (which I love driving !) with the wet belt engine. It's done about 62K miles (almost all at 70mph on dual carriageway) and I have a full service history with Ford parts........but the increasing mileage is starting to make me nervous.

I've a 2022 Fiesta 125 MHEV and my experience does not match that of TomsFocus above. The idle is very smooth but when driving the engine invokes a booming body resonance when between 1500rpm and 1800 rpm. I usually drive it in Sport mode, which disables stop/start, keeping the revs above 2000rpm and its a nice smooth drive, though with a throaty inlet growl when accelerating which some might enjoy but I would rather be a little quieter. It's a good smooth quiet motorway cruiser and even on the back roads I find it doing 10mph more than I think it is. It feels quite torquey and doesn't lack for power.

I only very occasionally find the regenerative braking disconcerting. Usually it is not really noticeable and I don't get any jerkiness. Perhaps Ford have tweaked the software for newer versions.

It is currently doing about 52mpg having started out at about 49mpg when new and tight, though my driving is mainly country roads or motorways with very little stop start town driving.

Like Andrew mine is a 2022 and I find no trouble with the idling. Once warmed up I sometimes have to look at the rev counter to check if the engine is still running when stationary, as it idles so quiet and smooth.

Looking at the comments so far I wonder if these engines vary, or whether it depends what car they're installed in?

I've only driven the MHEV (both 125 and 155 versions) in the Puma, and both seemed noisier and less smooth than the wet belt 140 Fiesta I had at the time. Or maybe the Fiesta was a good 'un?

 

My experience is with the 125 Mhev 2021 in the Fiesta ST-LX and it’s the best Ford engine I’ve had in 20 years. It’s very quiet and smooth, punchy when needed and efficient.

The drive modes are all slightly different, sport is a bit to ‘eager’ on the throttle but I like the regen effect when coasting to a stop. Normal’s ok, better throttle control and slight regen, similar in eco but more lazy throttle so you don’t hit the turbo too much.

Round town (outer London), is around 30mpg for 1-3 mile journeys.

Motorway is exceptional at over 60mpg when staying under 70 even with a bit of slip road, town driving. 
Definitely more powerful than the equivalent 125 wet belt ecoboost, but no real difference in turbo lag, it’s still there momentarily.

I’ve only owned two EcoBoost engined vehicles, a 2018 Fiesta 100ps and a 2021 Fiesta 125ps Mhev. 
 

The Mhev is simply amazing, with stop/start disabled you sometimes have to check that the engine hasn’t cut out when stationary, as it’s smooth and silent. I also appreciate that it’s a personal thing, but overall refinement seems improved over the 2018 wet belt engine. Moving on to the mild hybrid system, once again it’s personal, but I prefer the increased “engine braking” for control, I found the lack of engine braking in the wet belt when descending slopes something I never really got used to. I’ve come from bigger engined Petrol and Diesel cars.

I’m a bit of an EcoBoost Mhev fan to be honest, and combined with the excellent economy and build quality of my 2021 Fiesta I really rate them highly. I had one passenger side rattle which the dealer fixed by rerouting a wiring loom.

If I change cars I’ll probably stick with Ford and EcoBoost Mhev, the 170ps soon to be released in the Puma has caught my eye at the moment. 

 

 

1 hour ago, Aldridge Andy said:

The Mhev is simply amazing, with stop/start disabled you sometimes have to check that the engine hasn’t cut out when stationary, as it’s smooth and silent. 

Going back to my comment a couple of posts back, the Fiesta MHEV installation (which I haven't tried) sounds a lot better than the Pumas I drove, which were noticeably less refined than my wet belt Fiesta.

I have a 2023 Fiesta Titanium X 125 mhev, 7 months old now. It replaced a 2017 Fiesta Titanium 125.

the mhev is better in most respects, solid build quality, much improved 6 speed gearbox over previous cars 5 speed.

Refinement is very good and drives smoothly with an entertaining performance when required. Stop/start is very slick and operates unnoticed in the background.

Overall I am very happy with the car and I have not noticed any undue vibrations or harshness apart from a loose fuel line vibrating under the car when I increased the rev limit to 3000+ during running it in.

This was fixed by Ford dealer very quickly.

I like the regenerative braking effect and with practice it’s possible to drive for lengthy periods without using the brakes.

On 5/12/2023 at 1:57 PM, TomsFocus said:

Performance on the MHEV is great.  I had the 155ps version in the heavy Mk4 Focus (Active Vignale) and didn't miss diesel at all.  (Totally different experience to the non-MHEV 1.0 125ps Mk3 Focus I had before).

Economy was decent considering it's a petrol, 155bhp, and a heavy car.  Averaged 45mpg over the same roads that my 2.0 TDI 140 does 55mpg.

But refinement is where the MHEV is really lacking.  Very loud, very rough, just all round unpleasant with strong vibrations at idle and a horrible rattle while cruising even at 30mph.  People on here often complain about the engine cutting out at standstill, but that was my favourite part, finally some relief from all the noise and vibration!

I also hated the regenerative braking.  Obviously that's going to be part of any hybrid or EV, but I just don't think the mapping works well on these at all, trying to balance a manual petrol engine and regen braking makes town driving very jerky, and totally spoiled the drive for me.  When you lift off throttle or cancel the cruise control to roll up to a junction, the regen braking suddenly, but unpredictably, jolts the car within a few milliseconds. 

I've sold mine and gone back to a 'conventional' engine, with no electric assistance.  I am much more sensitive to things like noise & vibration than most people, so I would urge you to test drive one, rather than relying on anyone else's opinion.

Regarding reliability, I do believe these will generally be more reliable than the wetbelt version.  Ultimately there's a lot less rubber to clog the oil pump if the small belt degrades.  And you should get warning signs (oil pressure light or EML with VCT warnings) where the engine could still be saved with just a new oil pump belt.  It's also worth noting that the oil pump belt has a recommended replacement interval of 144k or 10 years.

If the engine is turned off when you brake linearly ... shouldn't you wear out the brake discs a lot more?? since you don't have the ability to use the engine brake on them..

24 minutes ago, luke514 said:

If the engine is turned off when you brake linearly ... shouldn't you wear out the brake discs a lot more?? since you don't have the ability to use the engine brake on them..

No.  Engine braking works regardless of whether the engine is running or not.  The engine compression is the same.  (That is why it is good practice to leave the car in gear when parked on a hill.)

You wear out the brakes less on the MHEV because of the regenerative braking.  When you lift off the throttle, the generator gets powered to recharge the 48v battery, and that creates a heavy engine braking effect, more so that non-hybrid cars, so less need to use the brake pedal.

1 hour ago, luke514 said:

If the engine is turned off when you brake linearly ... shouldn't you wear out the brake discs a lot more?? since you don't have the ability to use the engine brake on them..

The generator (basically a beefed up alternator) is still connected to the driven wheels and takes the load to charge the 48V battery.

EDIT: Tom beat me to it, lol.

Regen braking can be a real issue on EVs that don't get driven hard/far because the brakes hardly get used and then rust and go pitted instead.

1 hour ago, alexp999 said:

 

Regen braking can be a real issue on EVs that don't get driven hard/far because the brakes hardly get used and then rust and go pitted instead.

Easy way  to avert that issue on an EV is go into neutral on the odd occasion while driving  and that stops  the regen letting the mechanical brakes to operate. I do it once a week  on way to work on a stretch with incline. Discs are like new after 25k  a few of the more recent EVs do this automatically