Mpg Advice - Gen 7 140

[mojo7676]

hi. i've been trying to get a handle on what mpg i should expect. had th car for a couple of months - a 51 plate, with lots of s/h, 90k miles and i had it serviced a couple of weeks after buying it. engine oil was clean, but changed it anwway and i used denso sp plugs. Now, i've done a trawl and i get figures ranging from 25-35 for mpg. most of the driving i do is mixed - some local short journeys and a few slightly longer runs (not motorway) of up to about 10 miles or so in length. trouble is, i think, i only seem to be getting about 22-24 mpg which seems low to me - i'm not a lead foot but i do try to give it a bit of stick now and then. on that note, i've also noticed there isn't much in the way of acceleration - it makes a lot of noise, the revs climb well enough but it doesn't seem to pick up speed as i'd expect - reminds me of a mk1 mr2 i had which was kind of similar. my other car at present - a diesel vw golf (130 bhp) goes like the clappers in comparison. so - couple of questions, i guess: 1. if my mpg figures are low, any suggestions? 2. is there anything i should be aware of that might be making it perform less than well. i guess 1. and 2. may be related - but any comments or suggestions really appreciated. thanks. mojo

[T600]

Welcome.

That mpg sounds very poor to me; I'd be very unhappy with those figures. You could get much better from a 190 even with a heavy right foot. I don't know the weight of the golf, but I'd imagine it would be more than the 140 by some margin - especially an early Gen 7, so the Celica should feel quick compared to the Golf.

Hard to diagnose though if you have no warning lights. I take it the engine light comes on before you start the engine - otherwise perhaps the bulb has blown or been removed and there are hidden faults?

Also, it may not be engine related. When you say "the revs climb well enough but it doesn't seem to pick up speed as i'd expect" then are you suggesting that there's an increase in revs without a corresponding increase in road speed, because if so then the clutch is slipping and that would certainly give you performance and economy issues. (Unless this is just when you're setting off in which case it could be wheelspin which will also be a problem if you're doing it regularly).

The other thing to check maybe - if it's not the above - would be the brakes if that wasn't done at the service. Do any of the hubs seem to heat up too quickly or excessively (don't check this by touching them). Or raise each wheel with the handbrake off (taking precautions to make sure it can't roll away e.g. on Axle stands and the other wheels chocked) can you spin the wheels reasonably freely. A badly binding brake can seriously hinder performance and when it overheats the hubs it can quickly do for the wheel bearings too which makes things worserer.

Good luck with it and let us know how you get on. And don't forget to keep a close eye on the oil level with that engine!

[gazbrown]

I take it you know about the oil problems caused by the oval pistion rings in pre facelift models (your car). This problem not only causes hight oil consumption but by the very nature of the problem bad compression, (hence to check for damaged piston rings you do a compression check). Bad compression will give you poor performance and low MPG due to the fact that some of the power from the air/fuel ignition in the cylinder that is supposed to be pushing down on the piston head and driving the crank shaft, i.e driving your wheels is leaking past the piston rings.

Do you have high oil consumption? If so get a compresion test done, not sure how much a garage will charge but it should be fairly cheap as it only takes 15 min. If you have a mate with a compression tester check out the attachment below which shows you what to do and the values you should get.

Good luck and i hope your values are good otherwise you are possibly looking at big bucks to fix.

[mojo7676]

Thanks for the info, T600.

Don't know if the golf id heavier/lighter but it does have a turbo which helps it shift some.

no warning lights while driving - usual light up at key in/ignition/before starting - might get it shoved on one of those code reader machines sometime and see if that shows anything.

don't think the clutch is slipping - and the car does move, just doesn't to move too rapidly, is all. also, i can feel the clutch at biting point etc and all seems good on that front. and nope, not wheelspinning at all -

did check the brakes - all wheels spin freely - no binding or nothing, either. however, now that you mention, i do get a bit of noise from the brakes... sort of hollowness - not quite scraping but it seems something is happning. this only happens for a couple of minutes upon start up, esp. first thing in the morning.

thanks for reminding me about the oil - heard about that as an issue but mine seems to be eating very little (at present) -

anyway, will keep you posted if anything interesting happens...

mojo

[mojo7676]

thanks for that gaz - oil cons. doesn't seem to be too bad but will ask around about a compression test. thanks. mojo

[edwardio]

If you're mainly doing town driving and short journeys, the listed miles per gallon is 27.4 miles. So you're not too far off.

As for the acceleration, does the VVTI kick in at 4400 revs (or there abouts)? If it's higher or doesn't, you might have an oil pressure problem, which is prob a sensor on the way out.

Other than that, do you use any fuel cleaners etc?

[mojo7676]

thanks for the figures re town driving, edwardio - makes it a little easier to swallow, i guess.

not sure what's supposed to happen at 4400 revs - i can't tell if anything happens at all... second gear, floor it and the revs climb and there is acceleration but as i said before, it doesn't seem to get there too quickly... is something amazing supposed to have re this vvti thing?

as for fuel cleaners, nope - not yet. any recommendations?

thanks again. mojo

[edwardio]

I use STP fuel injection cleaner every 3k miles (about £4). You can use STP full system cleaner every 4k miles (about £15). You could use Redex (works out more expensive), or Acetone (I'm currently testing this).

The VVTI kicks in at 4400 revs (full torque hits at 3800 revs). Basically the car should noticably accelerate better at this point.

When was your clutch, gearbox and diff oils changed? I had mine done at 70k servie (should've been 60k) and I noticed a massive difference in the car.

[mojo7676]

will check out some of those fuel additives - can't see the effects being highly noticeable, especially over time but will see what happens. no idea when clutch gbox or diff oils were last changed - again, will chase up over th next couple of days.

thanks. mojo

ps - might try some of the lucas fuel treatment which i think works out a bit cheaper (if you buy a litre or so and, according to the person who recommended it, it's better, too - not sure how you can tell, but there you go).

[celica140sport]

i have probably the most oil thirsty vvti in the world but put it on the red line and it accelerates like a B**** nah what i tend to do when explaining the poor torque to friends is drive along in third gear keep tapping the accelerator and when u get to about 4k RPM youll notice the difference. as for fuel i do same sort of journeys as you for a test put 40 quid in at 110.9 i pay at the moment i got 250 miles on that see what you get. if u get more then ive got problems but i thought that was really good

[T600]

Why does nobody work to mpg any more?

That works out to slightly over 31mpg which is slightly better than standard around town figures, but way more than mojo's getting.

Perhaps you're getting some benefit from all that oil you're burning?

[mojo7676]

will play around with the driving style - keep at 3ish revs then floor it and see what happens. re mpg - i usually fill up to the neck, zero the odo, drive till it's on a quarter again, fill to neck and divide galls by miles driven to give me an mpg figure. costs me closer to fifty notes for 230-50ish miles, i recall. mojo

[edwardio]

It's much easier in the Celica to work it out by the tank full. As it's not fitted with a trip computer, working out how well we do per tank is easier.

Mojo, your diff, clutch & gearbox oil should've been changed in your 60k service. It might be worth checking your invoice from that service.

You'll be surprised how well fuel cleaners work. It's like kettles, irons, showers & washing machines. As limescale builds up, they don't work as well. Same as in engines. As carbon deposits build up in the camber, on valves & in the injectors, in means that the engine doesn't work as well as it should. A clean engine works better than a dirty one.

An easy way to check how dirty the engine is, would be to look at the plugs.

[mojo7676]

about to buy some of that lucas fuel stuff off eBay and see what happens after i've used a dose or two. - when i changed the plugs, the old ones didn't look bad at all - not really carboned up or anything.

s/h doesn't indicate what's been done and when so will get gbox oil changed today or tomorrow, depending on how my foot is...

i know this is a bit off topic, but does anyone else get a pain in the ball/heel of their right foot after driving their celica? only seems to happen if i drive for more than half an hour or so. In case you're wondering, i'm not pulling anyone's leg about this. Over the years, I've had countless coupes - including a 1983 celica 2.0st, a 1984 2.8 supra, a 1988 3.0 supra and every one of those was a pleasure to drive and gave me no pain whatsoever (except filling up but that was to be expected). a couple of years ago i bought a 1988 mr2 but had to sell that because whenever i drove it for more than half an hour, i'd be unable to walk the next day! the same is happening again now with this celica. I've tried messing around with driving positions but no matter what i do, the heel of my foot gives me agony - it's alright while i'm driving; usually kicks in (no pun intended) the morning after. It's so bad that i''ve been barely able to walk today. it's a weird one i know, but sadly, looks like i'll be selling this car simply because it's not a sustainable situation. maybe it's just me, but i'd be interested to learn if anyone else has suffered anything similar. again, apologies for going o/t. mojo.

[celica140sport]

sorry im thick dont acctualy know how to work out the mpg or really care tbh long as i do about 50+ miles to a tenner im happy. as for the foot ache i get that on long journeys but i think thats just a car thing in general u basicaly get to ly down in a celica anyway so all is good. my opinion the gen 7 is all about the looks and what a master piece it is indeed :D

[mojo7676]

bit of an update

1. had gbox oil changed today - can't say i notice any difference in terms of driving.

2. filled up and cost £43.03 @ 109.9 - worked it out to be around 26.5 mpg which seems not that bad compared to earlier figures. could be slightly warmer weather over last couple of days or so - noticed it doesn't take so long for the choke to knock off (there isn't any way to get choke off quicker, is there?)

3. bought some of that lucas fuel treatment stuff from eBay - not sure when it's gonna get here.

and

4. decided to swap celica with wife's vw - just can't drive this thing any more with the amount of grief it's giving my foot.

mojo.

[mojo7676]

well, the lucas stuff finally arrive - damned near 2 weeks after it was ordered and paid for. eBay, i'm learning, is not all it's cracked up to be.

anyway, used some in a tank and did a couple of hundred miles. here's the interesting bit:

made sod all difference in both mpg and running/performance.

might shove some more in on next fill up and see what happens. not holding my breath for anything at all noticeable, though.

mojo

[Sump]

Just as a comparison with a 6th Gen GT - I get around 25 mpg Urban driving - bit more on a run.