The Great Petrol Mpg Debate

[uumode]

OK... I'm jealous of other people's high MPG posted here and everywhere

- normally high 40's MPG on motorways, low 40's A roads and mid 30's town.

I'm puzzled at how the figures can be so high, especially as they are higher than the manufacturer's own official figures (which I believe are conducted on a rolling road with no wind resistance). - well, only puzzled because I can't get near those figures :)

Are folks simply reading off their trip computers (which is known to be inaccurate) or calculating from the £ value they put into the tank to where the fuel gauge was pointing last time (e.g. quarter tank).

They way I work out my MPG is by brimming the tank at the petrol station, zeroing the trip meter. Then at the next fill brim it again. Note the litres on the receipt divide by 4.55 to give me the usage in gallons. Then divide the reading on the trip meter by the gallons consumed to give the MPG.

For example this owner reports 40 MPG and 420 miles from a tank.

http://www.reviewcentre.com/review141604.html

However the Avensis' tank is 60 litres = 13.186 gallons

420 miles divided by 13.186 = 31.85 MPG??

I get about 31 MPG on free flowing A/B roads normal driving, and trying very, very hard only 34 MPG in my 1.8 VVTi Auto T4. Best ever so far is 35 MPG on same roads (my commute)

This review of a manual 1.8 VVTi reports 32.8 MPG which is not too disimilar to what I am seeing if you factor in my auto box. http://www.wintonsworld.com/cars/toyota-avensis.html

Putting my slightly envious position aside :P

what MPG's are Avensis owners getting when calculated from briming the tank and working out the MPG manually rather than looking at the onboard trip computer? Please state engine size, transmission, and tyre width (as wider tyres have more rolling resistance)

Thanks

[purvesh81]

1.8 Lean Burn (not vvti) Mk1 Avensis - Manual 5dr Hatchback with Toyo T1S 215/40/17 Hi-Octane wheels:

I get anywhere between 30-45mpg depending on how I'm feeling to drive, whether the AC's on or not and whether I'm consciously trying to keep the 'economy' light on.

"calculating from the £ value they put into the tank to where the fuel gauge was pointing last time (e.g. quarter tank)."

I tend to only put in £25 at time - ever (I'm thinking I'm saving weight here and the car doesn't feel so sluggish - therefore better mpg?) At best I'll get 250 miles from this.

I don't have a mpg calculator in my car, so I note the mileage to where the fuel gauge was pointing last time or when the fuel light comes on and manually calculate from there.

[Chris Dance]

My son has an 03 1.8 Avensis. He only uses the top grade petrol. The on board calculator always shows he gets over 50MPG.

In my T4 I use the low grade cheapest petrol. With air con ON, the on board calculator shows about 36MPG. Without air con about 40 MPG.

I notice I get a few more MPG with Esso than Tescos. It is not enough to worry about so I just use the cheapest garage for fuel.

Mr T recommended I use the top grade petrol now and again????? I do not understand why.

Is the on board calculator accurate? My sons local dealer says it is.

[campioni06]

My 1.8 vvti auto X reg does approx 250 miles for £25. Thats mostly in town driving and with air-con always on at the moment :D

I don't take too much notice of the figures on the trip-computer thing, and I don't put in any particular petrol, just 25quid worth when needed.

[jamesholden]

I used to get around 35MPG from my 3S-FE 2.0 Auto Avensis, the Camry has got a trip computer which is fairly accurate but I always calculate it myself and get around 28MPG, thats a 1MZ-FE 3.0 V6 auto, bit of town pottering and a bit of motorway everyday.

[Steve84]

I've just got off holiday in total did 270 miles just filled up with 27 liters. Thats around 6 gallong so that makes my total mpg average 45mpg approx, the trip computer was 2mpg lower. The car was fully laden with back seats folded 6 man frame tent all the other stuff that goes with a week away camping. On way back i did put me foot down in places so on the whole very pleased. On the whole the car does mid to high 30's in town driving on a run mid to high 40's is the norm.

[dazwan]

I usually get anywhere between 35 - 45mpg on my pre-vvti lean-burn 1.8.

You know your driving style can really affect your economy, in some cases you can knock about 30% off just by racing around everywhere. Considering how much people complain about the price of fuel, they could save more than just a few pence a litre by driving more economically.

[Mackers]

I get low to mid 30's, but i do live in North Wales (by the island at the top) and every day i have to drive about 1.5miles up, what is basically a mountain into my estate and the area i live in is all hills, so it does tend to hamper the MPG, on a good run on the A55 (main dual carrige way along to coast to Chester and L'Pool) i get top 30's on a good run.

[rf76]

I 'brimmed' my tank last Sunday in my 1.8 Avensis n drove to Lincolnshire and back, covering 350 miles and got home with 1/4 tank left. Had a/c running most of the way down there n windows/sunroof open once I got off the motorway. In total, I covered 435 miles on a full tank of 'gag' which I was quite impressed with. I'm also running an ECOTEC valve which claims to improve fuel efficiency.

[matty2767]

i dont take any notice of the onboard computer. and it is very difficult to calculate the mpg as just half a litre more or less will increase or decrease your mpg by alot (try it and see). i would say it is better to do it by miles and although my car is a diesel, unlike yours, it will do 500 miles before the red light comes on from a full tank.

[mcvpjd3]

I use a small app on my Garmin iQue (Palm) to calculate this. Over the last year my 2.0L Auto 03 T-Spirit averages at 26.2 Mpg, most of my driving is town driving. On the motor way I get about 33Mpg. The best I've ever had at fillup was 34Mpg. I normall use Tesco petrol, and during the summer I have A/C on all the time. Having a look through the charts on the app, I have much the same consumption during winter as I do during summer so the A/C can't have that much of an impact.

My onboard Mpg is usually no more that about 1Mpg out.

[Iain l]

I do a similar thing with a spreadsheet on my pocket PC. Over the last few months I generally get 33MPG but on a run at a steady 70+ have had 41MPG. Most of my driving is country roads and the car is a 2.0L Manual petrol. I always have the aircon on and have noticed a slight lowering of MPG when its hot. I recently had all the sensors replaced and since then the MPG has also dropped slightly. I also use the cruise control 99% of the time.

The onboard computer is usually +4 out at the low 30s and +8 on the high 30 to low 40s. Not too sure why its so inacurate, my Laguna was within +-1 and my old Vectra was always (and I still can't beleive it) spot on.

[matty2767]

my computer is always out by around +4 as well. today i filled up and it read 48.9mpg but when i calculated it was more like 44mpg. i have the 2.0 diesel. i dont notice any difference with the aircon on fuel consumption.

[Middleoftheroad]

My D4D T3X is just over a year old and has done 22k miles. During this period I’ve logged the number of gallons and the miles between each fill up and I’m very pleased with the average 53mpg it’s achieved. Most of my motoring has been on A-roads and motorways for journeys of 30+ miles but it does include some short runs in town. I also find the on board computer is about 4 mpg too optimistic.

[tubaman]

2002 1.8VVti:-

32 mpg crawling around town (av 19 mph)

28 mpg towing 1000kg folding camer unit

38 mpg at 70 ish

Motorway/A Road run 42-43 mpg

Hope this helps

[carday]

Being a taxi driver I am very conscious of the cost of diesel and the consumption, prior to getting my Avensis 2.0d4d I had a Ford Mondeo 2.0tdi Ghia which gave an average of 30mpg around town with A/C on all the time average cost per mile was 18p per mile. THe Avensis ,with A/C on all the time, is returning a high 38-40mpg and running cost is down to 13p per mile very impressive :) :)

[uumode]

Being a taxi driver I am very conscious of the cost of diesel and the consumption, prior to getting my Avensis 2.0d4d I had a Ford Mondeo 2.0tdi Ghia which gave an average of 30mpg around town with A/C on all the time average cost per mile was 18p per mile. THe Avensis ,with A/C on all the time, is returning a high 38-40mpg and running cost is down to 13p per mile very impressive :) :)

If Toyota added start and stop technology where the engine switches off at traffic lights (I guess similar to the Prius which uses Battery power) then it would be even better!

http://uk.cars.yahoo.com/car-reviews/car-a...rt-1004467.html

[silverarrow]

obc about +3 mpg

last 3 tanks to full

average mpg 42TRUE MPG MILES / GALLONS and air con on

BUT I CHANGE AIR FILTER EVEY 15 K AND USE COMMA INJECTOR CLEANER

[matty2767]

i had my diesel chipped and now the onboard computer says 54mpg previously it rarely went above 47.

[selfbuild]

Maybe I ought to do the same

Mine has never gone above 44 but according to the excel document that I use (and have done since I got the car (13 months and counting)), I average just over 53mpg.