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159 1750 TBi Economy

28K views 162 replies 59 participants last post by  epsonix 
#1 ·
What sort of economy are people seeing from the 1750 TBi engine...?

I have covered 500 miles in my 159 1750 TBi Ti Saloon so far... and have yet to see the Average MPG go above 25 mpg...

This is a combination of town and motorway driving... (around town only it drops to around 20 mpg...)

I saw 28 mpg when I had my BMW 325i SE Coupe... so was expecting at least the same.

I understand that the car's new... so maybe it'll improve... but wondered what other people were seeing...?
 
#108 ·
I´m new to turbo and noticed that when driving in the "right" gear the turbo pressure is more even and lower. For instance: When driving 70 kmph in 6th gear (1800 rpm) the turbo kicks in much more than when going as fast in 5th gear (2100 rpm). Actually both more economic and more fun (it seems).

To me it´s ok to cruise evenly at high speeds. The entertaining part is driving in lower gears.
 
#109 ·
Update 2...........

Ok, went back to experimenting with the TBi (with the 240bhp Mango Mod) 150 mile round trip, mainly motorway work - cruise set to a tad under 80mph...................36mpg - blimey!
So it can be acheived..........but to be honest, anoraks really don't suit me, so pedal-to-the-metal and back to the familiar 23mpg.

What is it about Alfas that somehow manages to anesthetize the rational mind?
 
#111 ·
I'm comparing Breras rather than the 159, but my 2.2 JTS returned 28mpg (measured over 2,000 miles) from my typical driving conditions and my 1750 TBi is a tad over 30mpg over a similar measurement distance.

I drive on cruise control at 70 mph on motorways and uninspiring A roads (like the A30 hereabouts) but really indulge myself in speed on country roads.

I didn't mod the 2.2. The 1750 is a far better engine to me, lots of torque, really responsive and beautifully smooth. I'd hoped to get a bit better consumption out of it, but the other advantages are myriad.
 
#115 ·
I am about to buy a 159 with the 1750 TBi engine and I am curious what engine speed do you keep when just slowly cruising in a city, let's say 30-40 mph? With 4 cylinder engines, I was always used to keep the engine speed above 2000 rpm at all times. The 1750 TBi engine has maximum torque at as low as 1400 rpm, does it mean that I can cruise normally at 1400 rpm and it will be OK for the engine? For a common 4 cylinder engine, this would seem too low speed to me.
 
#116 ·
In my experience it is difficult to drive in higher than 4th/5th gear around town and when you get to 40mph it's into 5th/6th.

It is quite a bit different to the 2.2JTS I had as the 1750TBi is higher geared and definitely quicker/quieter but probably not quite as flexible when the revs are really low (below 1500rpm) as you have to wait for the turbo to pick up and do its work but, again, that is probably down to the higher gearing.
 
#120 ·
My 159 2.2 JTS :cool: when driven sensibly will average 30mpg comfortable on my mix of urban/motorway run to work everyday, if I hypermile it will squeeze out 33mpg+ on the same run. However, if I drive it in a sporty manner the consumption will drop to 25/26mpg. I have to say the 2.2 JTS is a super engine, it revs really freely, no belt issues, no variator issue, uses no oil between services and plenty of power always on tap. The JTS reponds really well to annual oil changes and Mobil 1 oil. It does'nt sound as good as my old Twin Spark but requires less maintainence and tlc. Havnt driven a 1750 Tbi but the figures on paper look very impressive.
 
#121 ·
I managed 40mpg out of my 1750 tbi on a 150 motorway trip by sticking to Lane 1 and 2 as I was hoping to get home on the remainder of my tank. I didnt want to pay motorway fuel prices. I eventually gave up, filled up and drove like a "normal Alfa driver" on the last 50 miles.

I have driven 18,000 miles so far and as I log my mileage for work, I make a note of of my monthly average (Trip A) and 30.9 is the average monthly mpg since new.

I would like to get mid 30's especially with the high mileage I do and I think I'll be going back to diesel next time.

With my last 159 1.9 SW, I managed a monthly average of 39mpg and drove the thing hard (89mph on cruise-m/way). If I drove my TBI the same way as my old one, I'd be hitting the mid 20's so although the the TBI is faster...I'm driving it slower :(
 
#122 ·
Economy of the TBi is pretty average but what can you do?

I wince every time I fill the tank up since the latest tax rises so I've started to put in just over half a tank.

Do you think Alfa might introduce a hybrid? :lol:

The new Peugeot 508 diesel hybrid might be looking good in about 18 months time if fuel doesn't stop going up!
 
#129 ·
The same here. If I drive 80 kph at 6th gear, it shows something like 7 L/100km. It also seems that the turbo petrol engine needs different driving style than N/A petrols. With my previous N/A engines, I was used to push the accelerator all the way down pretty often at low revs. The engine didn't consume much petrol, but didn't accelerate much either. THe turbo engine accelerates nicely when pushed from low revs, but is also drinks a bit more :rolleyes:
 
#127 ·
My 3 weeks experience with my 159 TBi:

- Driving to work (30% city, 30% higway, 30% normal roads outside city): 11 L/100km
- Constant 130 km/h on higway: 10 L/100km
- Constant 160 km/h on higway: 11 L/100km

These values are about the same as with my previous car (2.2L atmospheric petrol, 200kgs lighter), so I don't complain.
 
#131 ·
1.8, 2.2 and 3.2

Reading with interest as I have recently being looking for a 2.2 Ti, as they are now in the 12K price range @35K miles.
Was looking at a 2.4 diesel, but have been put off by...
1. Diesel Noise, clatter and stench. We all buy Alfa's thinking of the V6 sound and end up with a 1.9 JTDM stinker.
2. The DPF/EGR issues that you WILL have. OK, they should of designed it to work, you can get it removed for 600 notes, but then you have insurance matters, increased premiums etc.

I had written off the V6 as just too uneconomical but looking at this thread, there is not much in it.
Previous experience with Mercedes and BMW is to just get the biggest engine available in said car, if the difference is say <5 MPG.

Down sides to a V6 is the servicing costs, depreciation and resale values. In 5 years road tax will be higher, petrol £2 + a litre, heck you would have to give it away; they could be on Pistonheads 'shed of the week' for less than a grand.

Who disagrees ?
 
#132 ·
Down sides to a V6 is the servicing costs, depreciation and resale values. In 5 years road tax will be higher, petrol £2 + a litre, heck you would have to give it away; they could be on Pistonheads 'shed of the week' for less than a grand.

Who disagrees ?
I got the TBi because it's the lightest of the range (110kilos lighter than the V6 - crucially in the nose), with a tweak it produces slightly more power-to-weight than the V6 with lots more torque, and with the prospect that the resale value will be higher. The only disappointment is the fuel consumption which is about the same as the V6 in real-world, spirited driving
 
#133 ·
A good 2 weeks of London driving and with 2 fill-ups it's steady at 23MPG (both on the computer and on a calculation of refilling to the brim). The first 8 miles is a cruise on a busy 3 lane dual carriageway (27MPG) and then a stop start 6 Miles.

But today on the (clear) M25 for 30 Miles each way and cruise control on.
Set at 80MPH out I got 25MPG and set at 70MPH for the return I got 30MPG.
 
#134 ·
Its still very poor Chris.

My wife has a Jeep 3.0 CRD Grand Cherokee and on a run, it does better than my TBI (getting over 30mpg)...why is that?

If BMW/Audi can offer petrol engines which give sensible mpg; why cant Alfa; after all its only a 1.8 with a turbo. I could understand if we were talking about the 3.2 V6. Don't get me wrong I'm a huge Alfa fan, but with the price of petrol and such low mpg, its beginning to hurt :(
 
#138 ·
25mpg at 80mph ?!! Only get 30mpg if doing 70?

That is very poor economy, that is about the same as an M3/911 (and my old 166 3.2 actually).

My 120k mile Saab 9-5 Aero estate which is a 2.3 turbo with 250bhp does considerably more too, 27mpg at 95, 30mpg at 85 and 33mpg at 75. Apart from styling obviously, why would i trade up to a TBi TI Sportswagon, as i'd be losing about 4/5 mpg and giving away 50BHP?

Shame, i'd expect what is a more modern version of broadly similar car (4cyl turbo estate) should be doing 4/5mpg MORE, especially since its down on power, maybe there is an issue with the fuelling/mapping of this engine which causes it to use so much in comparison to similar cars?
 
#140 ·
I'm sure it doesn't ! Its only about 215 Co2, so its not in either of the top 2 tax bands. I'm sure the regs have to account for all sorts of emmisions though, not just Co2.

The figures are bad compared to most other modern cars with equivalent power which do conform to the latest regs. My wifes 330i may be one of those for example, i drove that up and down to London the other week and it was 2/3 mpg better than my Saab at the same speed and, it would appear, about 9mpg better on a motorway cruise than the TBi. That's just wrong, a 3.0 straight 6 petrol being that much better than a 1.75 turbo 4 ? And BMW are phasing out the straight 6 in favour of smaller capacity turbo engines.........:confused:
 
#141 ·
I'd bet that the front light clusters have something to do poor fuel economy? They look great, but must create loads of dirty air and turbulance, look at any other car, yes they might look boring, but they have nice smooth noses that improve the aerodynamic performance.

OK it would make little difference at town speeds, but must be worth a few mpg at 50mph + ?

Want improved mpg? Get the clingfilm out and shrink wrap the front of your car :lol:
 
#144 ·
Yes, the lights may have an affect but they do have a splitter at the wing edge to hold the dirty air and the rest of the nose is clean. Alfa quote a fairly good Cda for the car but I bet that is with narrow tyres.

I find that the Ti TBi loses speed very easily when you shut the throttle. The old 156 rolled on very well at 50 MPH so that at speed camera sites I was always worried that downhill approaches needed care. In the 159 when I shut the throttle it loses speed quickly.

However, I can see that constant traffic lights in London hit the economy much harder than the 156 so I expect it is a combination of weight and tyres.
 
#142 ·
It depends where you buy your juice also - I find that with Shell or BP regular unleaded I can get 2-3 mpg more than the smaller brands... the main Shell station that I use is generally amongst the cheapest also... guess it may be the additives that the major suppliers put in their juice.... I'm getting 29/30 on my regular journey using Shell , compared to 26/27 using Total regular unleaded...
 
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