Fuel Issues

[Slickk]

I had my car serviced in November, I assume it was the intermediate one as it cost roughly £450 (I don’t have a service plan and have them carried out as and when required). Fast forward to February 2017, I’ve noticed a significant drop in MPG and also a huge drop in the indicated fuel range. Oh, in case you’re wondering, my driving style hasn’t changed at all.

Prior to the service, I’d fuel the old girl up when she showed roughly a range of 70 miles left in the tank. £30 of petrol would take that to 330+ without any issues – remember, this is indicated range. Over the past few times I’ve fuelled up, I’ve stuck to the same routine - £30 of petrol when the computer is showing me that there’s 70 miles left. However, the figure has dropped quite drastically to roughly 285 miles – I’m not too alarmed at this point.

This morning, I drove the car to work, parked up in the car park, lifted the bonnet, pulled out the engine oil dipstick to check the oil level, gave it a wipe, re-inserted it and pulled it back out again. It was showing that the oil was really very low, clean oil, but low in quantity. Another thing I’ve noticed is, over the past couple of months, when the engine kicks in, it makes an awful rattle. It’s not a particularly loud rattle, but it’s enough to notice that it’s different.

Any thoughts?

[Britprius]

There has been a considerable increase in fuel prices from November so your getting less fuel for your £30.

John

[Slickk]

6 minutes ago, Britprius said:

There has been a considerable increase in fuel prices from November so your getting less fuel for your £30.

John

My apologies John. I forgot to mention, due to the increase in fuel prices, I usually put extra fuel in. So it's more like £35 or sometimes even more.

[rayaans]

Most likely, the cold weather is to blame. 

No idea which part of Yorkshire you're in but where I live the temperature has fallen significantly since November. I believe it was about 10-12 degrees in November, its about 3-8 here on most days. 

From what you've said, you're gaining 215 miles from £35, and using a rough price of £1.18 for petrol thats about 29.7L. You're getting roughly 7.24 miles/L which is 32.91 MPG. 

Depending on what kind of distances you are doing, its very likely that the engine takes longer to warm up and sometimes may not even get fully warm. My wife's IS300h is doing about the same MPG so wouldnt really worry yet. 

My wife's IS makes a rattle upon starting the engine first thing on a morning - it doesn't do this when driving however.

 

 

[Slickk]

They're the same figures I got when I did the maths. I understand the rattle your wife's IS makes, I'm certain all IS car make the same rattle upon a cold stat.This rattle is an oddball one, it feels as though the engine is almost misfiring; quite difficult to explain. I usually let the car reach a reasonable temperature before I set off on a morning, so it's not as though I'm driving it from a cold start.

Earlier on, I drove to work - the car/engine was nice and warm and at a operating temperature. As I was parked, the car switched from EV mode to the engine and it made a rattle and felt like it was misfiring. On the other hand, the car kept springing up random service, engine change, oil filter change messages on the screen. The oil level does seem low, which is odd considering it was serviced in November.

[rayaans]

Just now, Slickk said:

They're the same figures I got when I did the maths. I understand the rattle your wife's IS makes, I'm certain all IS car make the same rattle upon a cold stat.This rattle is an oddball one, it feels as though the engine is almost misfiring; quite difficult to explain. I usually let the car reach a reasonable temperature before I set off on a morning, so it's not as though I'm driving it from a cold start.

Earlier on, I drove to work - the car/engine was nice and warm and at a operating temperature. As I was parked, the car switched from EV mode to the engine and it made a rattle and felt like it was misfiring. On the other hand, the car kept springing up random service, engine change, oil filter change messages on the screen. The oil level does seem low, which is odd considering it was serviced in November.

Have you got a service checklist stating whats been completed? 

If so, I would take it to the dealer and tell them whats been happening. Any chance of it being a bad batch of fuel?

[BigChange]

I would think 33 mpg is  low unless you are doing lots of short trips.  My last 2 fills - and I do a mix of many short (7 mile) trips and an occasional 130 miler - were 42.6 (Dec) and 41 (Jan). That's real world mpg (but I don't have the F-sport and I hardly use sport mode). I know it is colder in Yorkshire but that is a big difference.

Personally I would focus on the oil level.  Three months after service it should be full.  Did you get the stick properly in?.  It's a really awkward beast.  My car was last serviced 13 months ago and the dipstick level has not moved.  And there is no rattle on starting. 

[rayaans]

35 minutes ago, BigChange said:

I would think 33 mpg is  low unless you are doing lots of short trips.  My last 2 fills - and I do a mix of many short (7 mile) trips and an occasional 130 miler - were 42.6 (Dec) and 41 (Jan). That's real world mpg (but I don't have the F-sport and I hardly use sport mode). I know it is colder in Yorkshire but that is a big difference.

Personally I would focus on the oil level.  Three months after service it should be full.  Did you get the stick properly in?.  It's a really awkward beast.  My car was last serviced 13 months ago and the dipstick level has not moved.  And there is no rattle on starting. 

The hills here kill the MPG anyway. It doesn't recover as much MPG going down as it loses going up a hill. 

Also worth remembering that the IS300h does give a "Low Engine Oil" warning if its really low.

[olliesgrandad]

Personally I never let the car idle before driving off. I was always taught that it was bad for a cold engine to idle. I am averaging just over 42.5 mpg at present. I tend to drive in eco mode unless overtaking as I find the performance quite adequate. I never use supermarket fuel. When my father as alive we at one point owned 2 identical cars and experimented with fuel. We found that we always got better mpg and performance from 'branded' fuel.

 

[rayaans]

40 minutes ago, olliesgrandad said:

Personally I never let the car idle before driving off. I was always taught that it was bad for a cold engine to idle. I am averaging just over 42.5 mpg at present. I tend to drive in eco mode unless overtaking as I find the performance quite adequate. I never use supermarket fuel. When my father as alive we at one point owned 2 identical cars and experimented with fuel. We found that we always got better mpg and performance from 'branded' fuel.

 

Same here. I got told the traditional warm up was mainly for older cars with carburettors to prevent them stalling.

Also found that idling would probably take 10-15 mins to warm the car up. It'd be warm in 5 through normal driving.

[IS300Hdriver]

Would definitely get it seen to ASAP especially as it's still in warranty, very odd to have the oil level drop much at all, and all those messages to pop up.

In general every day driving as mentioned above, don't idle much before moving off, maybe just enough to get the engine oil circulating and starting to warm up. I've personally been quite surprised at how the recent cold snap has negatively affected mpg.

When I got mine I left the car in normal mode due to liking the throttle response but after struggling to get above 40mpg in the city, I now keep it in Eco and get at least 5mpg more. Lots to be said for coasting where possible, and when braking, do it well in advance and gently to keep the needle as high as possible on the charge gauge.

Also an advocate of branded fuels, usually Shell, BP and Esso. To be fair it's all just about the additives, I think with any cars that stop and start engines frequently, the injectors need some TLC. Much more so on diesel cars (as I found out).

 

[DanD]

I think that if you check the oil level just after a drive, the level will always appear low on the basis that most of the oil will still be somewhere around the engine.

Before checking your dipstick, you should wait at least 5 to 10 minutes to allow gravity to do its bit and for the oil to find its way back down and collect into its reservoir (sump?)

[B1001]

I noticed the engine revs high in Park from start up (1750 rpm) and drops to 1000 in drive. It always sounds loud, I try to get moving as soon as possible.

Also I only use Sport mode when the engine is warm.

I use Eco from cold and for 99% of my journeys. I don't use Normal mode.