low mpg on '06 2.2 i.ctdi spotr

[georgeian]

I have recently bought a CR-V 2.2 i.ctdi sport. I can only manage to get around 38.5 mpg. I drive in a conservative manner and don't race through the gears but I can't seem to be able to improve my mpg. The journey I do every day is around 12 miles each way. My brother has the same model and gets a return of 47mpg!! I find a difference of ten mpg a bit hard to swallow. I'd like advice on what cures there are to bettering the situation.

[Jimbo_EX]

I found that using Castrol Edge Turbo Diesel 0W-30 fully synthetic oil upped my avarage mpg from 35 to 37, as did using shell diesel rather than supermarket fuel. To be honest though, achiving 47 sound slike a tall order, as ive never had mine over 42 for a journey. Over the last 3 k miles ive avaraged 37mpg so what you are getting sound normal to me..

[Hughesy]

My lifetime average is 40 mpg, but it is improving all the time as the engine beds in (about 9k miles otc so far).
I can regularly acheive 45 mpg over a whole tank.
With very careful driving I can get 50 mpg, but it's hard to keep that up over a whole tank (given cold starts and short trips).

Here's my tips:

1. Speed. This is the main killer of mpg.
Approximately it works out like this cruising on the flat:
30 miles per hour = 55 mpg
40 miles per hour = 50 mpg
50 miles per hour = 47 mpg
60 miles per hour = 45 mpg
70 miles per hour = 40 mpg
80 miles per hour = 36 mpg
90 miles per hour = 33 mpg

Because of the poor aerodynamics of the CR-V, the best mpg is not acheived on the motorway. Take a shorter route on A roads doing 50-60 miles per hour, and you will get much better mpg that cruising at 70 mph on the motorway.

2. Gear. The engine can be laboured a lot more than you think. Change up asap. Change up when slowing down (accelerating would labour the engine, but it's ok because you aren't). 30 mph round town should be in top gear. Good mpg requires lots of gear changes!

3. Anticipation - avoid braking and change down through the gears as you slow down to a stop (don't hold the clutch in) this cuts fuel to the engine.

4. Tyres - try running about 10% more than the recommended pressure

5. Turn off A/C.

6. Don't use cruise control. Slow down slightly going up hill and speed up slightly going down hill.

7. Fuel. Esso fuel and BP Ultimate fuel seem to get better mpg than Tescos.

For those in the US: all mpg in this post (and the original poster I assume) are UK mpg. multiply by 0.83 to get US mpg.

I'm in the habit of taking pictures of my trip computer just before refilling, see below. The distance next to the B is how far that mpg has been acheived over (I always reset the B trip when I fill up).

[georgeian]

I met a guy whilst refueling just after I bought my CR-V and he sold magnets that fitted to the fuel system andclaimed that they could reduce fuel consumption by as much as 10 mpg. It sounds a bit iffy but it leads me to ask if anyone else has heard of this before. He also showed me stats and figures relating to fuel savings using magnets, they looked genuine. As I hadn't time to go into it further with him I was going to contact him later.He gave me his card but I have lost it.So, can anyone shine any light on this topic?

[Hughesy]

I met a guy whilst refueling just after I bought my CR-V and he sold magnets that fitted to the fuel system andclaimed that they could reduce fuel consumption by as much as 10 mpg. It sounds a bit iffy but it leads me to ask if anyone else has heard of this before. He also showed me stats and figures relating to fuel savings using magnets, they looked genuine. As I hadn't time to go into it further with him I was going to contact him later.He gave me his card but I have lost it.So, can anyone shine any light on this topic?

It's a scam.

[Jimbo_EX]

when coming to a halt better to stay in the gear your in and declutch when necessary before stopping. Changing down to slow down just puts more wear on the transmission.
Gears are for accelerating, brakes for stopping.
Brake pads are cheaper than clutches.

[Hughesy]

when coming to a halt better to stay in the gear your in and declutch when necessary before stopping. Changing down to slow down just puts more wear on the transmission.
Gears are for accelerating, brakes for stopping.
Brake pads are cheaper than clutches.

Maybe avoiding downchanges saves a bit of wear, but it's not the best for mpg.
If you are in 6th gear (which you should be) when decelerating, you have to declutch at about 800 rpm, which is 25 mph. Even in 3rd gear 800 rpm = 14 mph. Coasting to a stop from such high speeds is a waste of fuel, because if you were in gear no fuel is injected. Out of gear, the engine needs to inject fuel to idle.

If my gearbox lasts 190,000 miles instead of 200,000 I don't really mind :)

[bernithebiker]

My lifetime average is 40 mpg, but it is improving all the time as the engine beds in (about 9k miles otc so far).
I can regularly acheive 45 mpg over a whole tank.
With very careful driving I can get 50 mpg, but it's hard to keep that up over a whole tank (given cold starts and short trips).

Here's my tips:

1. Speed. This is the main killer of mpg.
Approximately it works out like this cruising on the flat:
30 miles per hour = 55 mpg
40 miles per hour = 50 mpg
50 miles per hour = 47 mpg
60 miles per hour = 45 mpg
70 miles per hour = 40 mpg
80 miles per hour = 36 mpg
90 miles per hour = 33 mpg

Because of the poor aerodynamics of the CR-V, the best mpg is not acheived on the motorway. Take a shorter route on A roads doing 50-60 miles per hour, and you will get much better mpg that cruising at 70 mph on the motorway.

2. Gear. The engine can be laboured a lot more than you think. Change up asap. Change up when slowing down (accelerating would labour the engine, but it's ok because you aren't). 30 mph round town should be in top gear. Good mpg requires lots of gear changes!

3. Anticipation - avoid braking and change down through the gears as you slow down to a stop (don't hold the clutch in) this cuts fuel to the engine.

4. Tyres - try running about 10% more than the recommended pressure

5. Turn off A/C.

6. Don't use cruise control. Slow down slightly going up hill and speed up slightly going down hill.

7. Fuel. Esso fuel and BP Ultimate fuel seem to get better mpg than Tescos.

For those in the US: all mpg in this post (and the original poster I assume) are UK mpg. multiply by 0.83 to get US mpg.

I'm in the habit of taking pictures of my trip computer just before refilling, see below. The distance next to the B is how far that mpg has been acheived over (I always reset the B trip when I fill up).

1. Definitely - aerodynamic drag on the car increases with the square of your speed, so 80 to 90 is much worse than 70 to 80. But beware! Driving at 40 on a clear A-road will not make you popular!!

2. I tend to change up at about 2000rpm. I find the engine is not so happy below 1300rpm, and is certainly quite slow to respond. However, from time to time, I like to give the engine a good clear out, by revving through the gears almost to the redline. Often when pulling away, I go 1st, 3rd, 6th.

3. Anticipation, yes, it's the motto of the fuel saver. No need to change down through the gears when stopping, just leave it in the gear you're in and brake.

4. Yes, this helps, but handling suffers a bit and the ride is slightly more choppy.

5. Yes, but you can use it when going down steep hills or when coasting a halt.

6. Yes and no. If the road is mostly flat i say use it. The car will keep you at EXACTLY x mph. If it's a human, your speed will fluctuate by x +/- 2 or 3mph. All those little accelerations add up to more fuel being used. BUT if it's hilly, then the cruise will strain to maintain speed going up, so in this case it may be better to turn it off.

7. I have examined this carefully, and evidence from the majors for their 'super fuels' is very thin on the ground. If they are so good, then why can they not just show us a concrete example of this 'super-performance'. In any case, the price difference is so great that any potential saving is more than cancelled out by cost. Remember, EN590 (road DERV) must have a cetane number of 51 min. Car designers design their engines around this specification, not 54+.

For the record, my best 100 mile round trip consumption is 56.5mpg (UK), Usually it's about 47, and never below 40 (unless towing the boat!). If your below 40, you are either a boy racer or you have money to burn (or both!)

[Jimbo_EX]

Maybe avoiding downchanges saves a bit of wear, but it's not the best for mpg.
If you are in 6th gear (which you should be) when decelerating, you have to declutch at about 800 rpm, which is 25 mph. Even in 3rd gear 800 rpm = 14 mph. Coasting to a stop from such high speeds is a waste of fuel, because if you were in gear no fuel is injected. Out of gear, the engine needs to inject fuel to idle.

If my gearbox lasts 190,000 miles instead of 200,000 I don't really mind :)

Thats what I mean, just take your foot of the accelerator, dont go into neutral, leave it in the gear you are in. If you need to scrub more spped of gentley apply the brakes, dont use the engine or teransmission by changing down.

[Jimbo_EX]

Thats what I mean, just take your foot of the accelerator, dont go into neutral, leave it in the gear you are in. If you need to scrub more spped of gentley apply the brakes, dont use the engine or teransmission by changing down.

And besides, when in the real world do ever coast to a complete stop without touching the brakes. By the time you have to declutch from 6th your onle a couple of seconds from coming to a halt.

[Hughesy]

7. I have examined this carefully, and evidence from the majors for their 'super fuels' is very thin on the ground. If they are so good, then why can they not just show us a concrete example of this 'super-performance'. In any case, the price difference is so great that any potential saving is more than cancelled out by cost. Remember, EN590 (road DERV) must have a cetane number of 51 min. Car designers design their engines around this specification, not 54+.

For the record, my best 100 mile round trip consumption is 56.5mpg (UK), Usually it's about 47, and never below 40 (unless towing the boat!). If your below 40, you are either a boy racer or you have money to burn (or both!)

Take your point about super fuels. However, I have had some bad tank-fulls from the supermarket. The whole tank I keep thinking why can't I get better mpg. Then shortly after filling with brand name fuel like Esso or BP it all goes back to normal. It's only anecdotal, but now I fill with brand name fuel if I can get it at the same price.
I don't use super fuels these days, because of the price, and I will not keep the car long enough to see any long term benefits.

[Jimbo_EX]

I have the same experience. Branded fuel simply gives me better mpg than the supermarket. In my case Shell vs Tesco..
I've tried V power diesel and found no difference compared to normal Shell diesel. Except the price:eek:

[bernithebiker]

I have the same experience. Branded fuel simply gives me better mpg than the supermarket. In my case Shell vs Tesco..
I've tried V power diesel and found no difference compared to normal Shell diesel. Except the price:eek:

Can you really tell a difference? Fuel consumption is affected by so many things; even if you are doing the same journey every day, you will have different conditions like; wind, rain, extra weight on board, traffic conditions, temperature, etc. All these things will affect your fuel consumption, so it must be very difficult to say that a change is simply down to the fuel.

It is only really possible to measure different fuel's effects on comsumption under lab conditions, where all the above variables can be removed.

Shell, BP, Total, etc. all sell EXACTLY the same fuel as the supermarkets, to the exact same specifications. They simply apply a detergent additive (which some supermarkets also do). Their 'super-fuels' eg. Ultimate, Excellium, etc. also have additives for improving cetane number (not index) which in theory, improves combustion slightly (but again, where is the hard evidence, and watch out for the price....)

The only possible reason that one tank of fuel's consumption may differ from another is if it was contaminated with say water or sediment. I think there is alot of psychology involved in thinking that a major's fuel 'must' be better. But bear in mind that supermarkets are more often than not supplied from the exact same refineries that supply the majors. And again, all fuel sold in Europe must meet the stringent EN590 specs, which cover over 20 aspects.

[Jimbo_EX]

Yep.
The average mpg readout, backed up by manual calculation, i get an increase of upto 2 mpg from Shell diesel vs. Tesco. This is with the same weekly commute etc.
I have noted this several times as I have swapped back and forth due to Shell being cheaper unless Tesco have their 5p a litre discount offer on..so ive used both over 15k miles.

As another issue, ive noticed by comparing to manual calculation, the average mpg shwn on the computer is usually about 1 mpg under what i acrually get..

[RX729]

I wish we had diesel here in the states...

[electric V]

My father and I were talking to a mechanic and he said that the supermarket fuels were worse than the name brands. He said that he had to do some work on cars than were running only on supermarket fuel and they got drastically bad preformance. Magnets will do nothing to increase your fuel economy.

Also I was wondering if you use a higher octane fuel in a deisel wouldn't you get better fuel economy because the higher the octane rating the higher the heat must be for the fuel to burn. So would a diesel engine want to sip less fuel in order to get the desired burn or would it not matter because the compression is too great.

I love here in the US and am still waiting on the arrival of the deisel V.

My V is a 1998 with a 2.0 liter/litre engine and i get about 25 US MPG so would that calculate into 30 UK MPG?

[tsmithvt]

Also I was wondering if you use a higher octane fuel in a deisel wouldn't you get better fuel economy because the higher the octane rating the higher the heat must be for the fuel to burn. So would a diesel engine want to sip less fuel in order to get the desired burn or would it not matter because the compression is too great.

An "Octane" rating applies to gasoline and other fuels burned in spark ignition engines. It is the measure of a fuel's resistance to pre-ignition/detonation.

Ignition quality for diesel fuel and other fuels used in compression ignition engines is measured by its "Cetane Number".

Yes, a higher "Cetane" diesel fuel will yield better overall performance, fewer emissions and easier cold weather starting.:)

[bernithebiker]

My father and I were talking to a mechanic and he said that the supermarket fuels were worse than the name brands. He said that he had to do some work on cars than were running only on supermarket fuel and they got drastically bad preformance. Magnets will do nothing to increase your fuel economy.

Also I was wondering if you use a higher octane fuel in a deisel wouldn't you get better fuel economy because the higher the octane rating the higher the heat must be for the fuel to burn. So would a diesel engine want to sip less fuel in order to get the desired burn or would it not matter because the compression is too great.

I love here in the US and am still waiting on the arrival of the deisel V.

My V is a 1998 with a 2.0 liter/litre engine and i get about 25 US MPG so would that calculate into 30 UK MPG?

Octane and cetane ratings are pretty much the opposite of each other. High octane = high resistance to ignition under compression, high cetane = low resistance to ignition under compression.

As for the supermarkets, I can only say this; where do they get their fuels from? A refinery. And who owns that refinery? Esso, BP, Shell, Total, etc... Therefore, more often than not the supermarket fuels come from a 'major' refinery. The only difference is any additive that a company might apply at the refinery gate. The base fuel is from the same tank. It all meets Euro specifications and limits, it has to by law.

As an example, there is a Total refinery at Immingham, near Grimsby. No doubt there is a Tesco, Sainsbury, supermarket etc in Grimsby. No prizes for guessing where these supermarkets' fuel is coming from. Freight is very expensive these days; the refinery will sell all it can locally before having to export by ship. And Total will have sharing agreements with Shell, BP, etc. so that Total can supply local BP stations and BP can supply local Total stations wherever it has a refinery.

Marketing is a powerful tool - why else do Shell, BP et al sponsor Formula 1, Le Mans, etc? So they can sell you overpriced fuel. If their fuels really were so very much better, why do we not see adverts stating real evidence that proves the fact? (Not this kind of thing; "with our fuel, you MAY get UP TO 5% better economy!!!) - that is utterly worthless.

I still maintain that it is extremely difficult to ascertain a difference of a few mpg betwen tanks of fuel, as it is impossible to apply the exact same conditions for each tank full. Having used BP, Total, Elf and supermarket diesel, I have never seen any difference between them.

The only specification that could feasibly improve economy, smoothness and noise is the cetane index and number (index is calculated, number is measured in an engine). ALL road diesel in Europe must be 46 and 51 minimum respectively. The standard diesels from BP, Shell, Total and Esso do not even CLAIM to improve cetane (just detergents, etc) so there is no reason why their standard fuels would return better economy.

[electric V]

Thanks for the replys I had no clue as to what deisel fuel related to gas. I have never own a deisel vehicle but I had been in one my mother has gotten worse gas mileage using supermarket fuels rather than name brand I am only saying what I know.

Yes, the exact conditions when driving the vehicle will affect what your MPG is. But hear in sunny California ther weather hardly ever changes enough for it to make a real difference. I am not her to persuede anyone but just to say what I know.

[Davidg_croydon]

I have a 6 month old 2.2 EX CTDi CR-V. It's done about 2,000 miles since new and is our first diesel (and also our first car bought brand new).

I'm concerned that I'm not getting the mpg (or anything like) claimed by Honda.

Our average (claimed by the trip computer) for the 2,000 miles is 30.1 MPG. In Town driving we get about 28 MPG and motorway about 37 MPG.

Does this sound reasonable? The first 100 miles were much worse than this, at around 20 MPG.

Does it improve over time?

Thanks,
David

[bernithebiker]

Yes.

As the engine beds in, not only will fuel consumption improve, but the engine will become free er revving.

[Cobh]

Re fuel standards. One point I would query is that EN 590, as a current quality mark, is a little deficient! It makes no requirement re detergency, so some supermarket fuel will skimp on important additives, but maintain EN590 minimum. Now, some tests have not detected any difference, but then they were fairly skimpy themselves:D The engines would have to be either run for tens of thousands of miles or inspected internally (borescope) for valve/piston crown deposits and compared. Did they do this? Consumers Association did not seem to.

[bernithebiker]

True, EN590 makes no requirement for detergency. However, here in France, almost all the supermarkets do add a detergent, and I would imagine some if not all UK supermarkets do the same.

It is not easy getting information on things like this - in fact even with some of the 'majors' eg. Esso, etc. it is not clear if there is a detergent or not.

[Captain Vallo]

he sold magnets that fitted to the fuel system andclaimed that they could reduce fuel consumption by as much as 10 mpg.

Yeah and when not driving, you can wear them on your wrist and clear headaches and improve general wellbeing. You may also be able to wear them in such as way as to make some of your personal 'belongings' bigger and longer. Put them in your hat and you may achieve a science degree or two.

[Captain Vallo]

I've come from a Honda Accord tourer diesel to this CR-V (16k on clock) diesel and was initially a little dissapointed by the number of miles per tank comparison.

In short, I am currently travelling to/from midlands to SE each week, mostly motorway at 80mph. I tend to travel when traffic is lighter (to avoid M25 carpark). I then stay locally undertaking small journeys.

In my accord I was getting there and back with about quarter of a tank to spare (about a 400 mile round trip).

However the CR-V is only just doing the same journey and is closer to empty.

However (again), I have discovered the CR-V tank is considerably smaller.

After messing about with various numbers on spreadsheet I have come to the following conclusion:

I think that the Accord's computer mpg figures were less than reliable, and rarely (if ever) did my refills appear to match the trip computers figures. As a rule the litres (x10) to fill were more than the miles dones. eg 470 miles = 49 litres to fill. I always filled the tank and the accord had an automatic reset on one set of figures. I can only remember once it needing less litres (x10) than the miles done.

Often the accord would tell me that i was achieving 50+ mpg with conservative driving, yet refil would still be same factor.

However, the CR-v (with only 2 weeks ownership) computer appears to be a little more accurate and so far both the refills and the clock showing 38mpg. This means the CR-V is about 5 or 6 mpg down on the Accord which is what I was expecting.

To summarise I appear to be getting about 38mpg, but will keep accurate data and update later.