Hire Car Blues

[Dapple]

Aaaagghhh. My poor Prius has been bumped in a car park. I was stationary and someone reversed into me.

My insurance is sorting it thankfully, and I have a 1 year old hire car. It looks very nice actually, a top spec Avensis Diesel Auto saloon in a maroony colour. Its got all the toys. Its roomy and road noise is a little better supressed over the Prius. The seats seem ok and the boots big though difficult to access as a saloon. The kids like it. Well sort of.

However my hilly urban commute is showing 22.8 mpg average on the cars tripmeter and by the amount of the stinky expensive stuff I have to keep putting in the tank I believe it. The car is showing a best mpg figure of 41 mpg (it has 30k on the clock) which seems fairly disastrous.

Setting off is easy though as long as you have a gap that you could get a fully laden 38 tonner into. Simply floor the throttle and then spend the wait retuning the radio until the gearbox decides to wake up. Then the under bonnet clatter rises to a cacophony and eventually you start. The engine noise then sounds as though you are being very closely pursued by a 1985 post office van. Alternatively you can of course press the sport button and repeat the process. This still leaves time to flick between a few radio stations but follows this with some comedy wheelspin and traction control enhanced lurching. A third alternative is to put it in manual and use the steering wheel flappy paddles to try to tell the gearbox you'd like to proceed forwards now please.

I must admit I had forgotten the feeling in an old-school auto when you come off the throttle. That odd feeling of no control, of the car simply running away freewheeling with the revs dropping back to idle speed, and the drive effectively disengaged. Its so last century, I find it hard to believe this car is (nicely) built by the same clever people that built my Prius and SWMBO's Auris HSD.

Come back soon Dapple (the Prius's name-the kids named it after the colour (Dacuma)), we miss you a lot.

[Heidfirst]

"However my hilly urban commute is showing 22.8 mpg average on the cars tripmeter and by the amount of the stinky expensive stuff I have to keep putting in the tank I believe it. The car is showing a best mpg figure of 41 mpg (it has 30k on the clock) which seems fairly disastrous."

Sounds like a 2.2 D-CAT auto - the thirstiest engine (thanks to the D-CAT 5th injector) mated with the thirstiest gearbox... If you have a short urban commute it's probably also never reaching optimum operating temp. The 1.8 petrol CVT would probably give you better mpg.

At least according to the stats acceleration should be quite rapid so it's either out of sorts or the ECU has learned the driving habits of a granny :p & could do with a reset,

Interesting what you say about traction control - I've never seen the traction control light come on in my manual T27 or felt a lot of wheelspin when setting off & my T25 used to often enough that I've noticed the difference.

[Grumpy Cabbie]

Ah I'd forgotten about the momentary delay with a diesel before setting off to allow time for the turbo to spin and give some power.

I really don't get why people go on about diesels so much. They're fine in a Range Rover or truck (or train), but in a car?!?! Even the quietest sound like tractors to me. Just wind your window down at a busy traffic lights and smell in the clatter, clatter, chug, chug of the dreadful things, and then literally smell in that sweet pungent smell of half filtered diesel fumes.

If they were invented today, they'd never be allowed.

[FROSTYBALLS]

Alternatively you can of course press the sport button and repeat the process. This still leaves time to flick between a few radio stations but follows this with some comedy wheelspin and traction control enhanced lurching.

Tyres?

We're having some issues with our i20 where the front tyres aren't gripping too well on wet or damp roads - wheelspin and lack of grip when moving away from junctions, etc, Tyres (OE fit Kumhos) only down to 4mm. So looking to change them in the next couple of weeks.

[Cyker]

Yeah, if it's a hire car the tyres will probably not be in the best of condition, esp. as it is a high torque diesel! They chew through front tyres like nobody's business if abused. Esp. if cheap LRR tyres have been stuck on it.

The acceleration issues are likely due to a mix of the ECU and the autobox. I'm not sure if that car has an MMT-type autobox or a CVT, but either way both are rubbish at dealing with sudden application of high torque compared to manuals and the ECU will prevent the engine from delivering its maximum torque in low gears to protect the autobox from being torn apart.

A well balanced turbo-diesel shouldn't have any noticeable turbo lag as diesel's strength is at low RPM while turbos come alive at high RPM - They compliment each other far better than with petrol engines. Any acceleration lag from the engine itself would be due to the heavier cranking parts and especially the heavier flywheel.

I don't think I've driven an automatic D4D but all the manual ones I've driven have been great fun to drive; Good launch and torque that could tow a house It sucks that yours is being held back as it should be a load more responsive and enjoyable to drive than it sounds :(

Should have gotten a manual one!

The actual problem tho' is that you have been spoilt by the HSD!

It is literally the best autobox you can buy so it's natural going back to other types of autobox would feel pretty crappy and out of control by comparison! ;)

I hope yours gets fixed and returned to you quickly so you can go back to enjoying it; I know what it's like having a hire car that just doesn't sit well...!

[Heidfirst]

it has a 6-speed conventional torque converter autobox.

The lag problem isn't really the turbo etc., it's the drive by wire throttle which is programmed to minimise emissions/fuel consumption. It's pretty common on most modern cars incl. petrols.

[Grumpy Cabbie]

it has a 6-speed conventional torque converter autobox.

The lag problem isn't really the turbo etc., it's the drive by wire throttle which is programmed to minimise emissions/fuel consumption. It's pretty common on most modern cars incl. petrols.

I floor mine and it's pretty much instant, even accounting for the engine having to start immediately. Ideal for nipping through gaps on roundabouts.

[Dapple]

Well it's got good tyres on with plenty of tread, and careful treatment has nursed it up to 25 mpg which, c'mon is 10% better!

The terrible lag is ever-present though, you have to be very careful getting out of junctions.

To be fair to it, it's a successful big baggy motorway cruiser that's simply completely out of its comfort zone in urban land.

The engine and gearbox combo though is poor. I had a 3 litre turbodiesel auto Signum a decade ago that, although a Vauxhall with all that that entails, had a very successful engine/box combo with little lag and intelligent gearbox programming that, for example, would downshift when descending hills with cruise control engaged, in order to at least attempt to maintain the set speed, the knock-on benefit being that this would also allow over-run fuel cut-off to function. This Avensis simply drops out drive on the over-run and drops to idle but has to fuel this. I am therefore consuming diesel as well as brake pads descending hills!

I am sure that there are better drivetrain combinations available in this well-built, fairly handsome, thirsty and tricky to drive car.

[Dapple]

Well I gave the Avensis a gentle stroll down the M62 today. Reset the fuel trip when up to speed and did 30 miles East at 60-70 mph, then returned West at the same speeds. The gearing gave me 70mph at 2000rpm so I had high hopes. I averaged 38 mpg. Then left the motorway for urbanland, reset the trip again, and returned to 22.8 mpg.

So, if we believe the mpg readouts in my Prius, and in my rented Avensis autodiesel, then I am losing 25 mpg both urban and motorway, and using dearer fuel.

Now I would be the first to admit the science is far from exact, but I hope my car returns from the bodyshop before my wallets empty!

[Grumpy Cabbie]

I'd driven an Avensis before and whilst a nice drive and a smooth and quiet (for a diesel) engine, the economy was pants. I tried my hardest and only got about 43 mpg. I'd be taking my Prius back if it was getting that.

Horses for courses and I know the Prius ain't perfect, but I bet this experience makes you appreciate it.